Series 31E

Hand fine matt grounded stainless steel case with 42 mm diameter, finely decorated hand winding Unitas pocket watch movement modified to an indirect center second and a deep black contrast dial with handmade hour and minute hands. The new Model 31E is certainly one of the best pilot watches we've ever built.

An extraordinary pilot watch

For our Series 31E we use a fully satinized i.e. by hand fine matt grounded stainless steel case with 42 mm diameter and 11.95 mm height and recase the HS81 manual wound movement in it. This watch is powered by the finely decorated hand winding Unitas pocket watch movement which is modified to an indirect center second and a special feature, which is visible only for the view of the wearer - the seconds zeroing.

To precisely set the time of a wrist watch most movements are equipped with a second stop – when the crown is wound, the second hand doesn’t move. The seconds zeroing is a much rarer design. When the crown is wound, the second hand continues to run until it reaches “60” and then it automatically stops – thus it is possible to use a time signal to set the watch to the second.

Contemporary our model 31E is pressure-resistant up to 10 bar and equipped with sapphire glasses on front and back side. The watch wears a deep black contrast dial and handmade hour and minute hands. Like all the hour indices and the marking triangle, these steel pointers made in Saxony are coated with white luminescent material.

For the love of details

Also this watch was developed and built entirely in Germany - that is, Case, dial, hands, bracelet and clasp are all produced in Germany. The pocket watch movement we use is decorated, modified and regulated in our workshop in 5 positions. For this reason we engrave “Frankfurt” on the watch back.

Made in Germany

Technical details

Movement

Calibre HS 81
Base: UNITAS 6497 Lépine. Modified as per a construction by Helmut Sinn
Indirect center second
Second stop at 60 when crown is pulled
18 jewels
18000 vibrations per hour; 2.5 Hz.
Movement diameter 16 1/2‘‘‘ (36,6 mm)
Incabloc shock protection
Glucydur balance
Nivarox hairspring
Triovis precision adjustment system
Movement decorated with Geneva Stripes , blued screw hads, crown wheel and ratchet wheel with solar finish
Power reserve approx. 40 hours

Functions

Hours, minutes, indirect center second
Second stop at 60 when crown is pulled

Case

Stainless steel hand satinized
Sapphire crystal glass, domed, anti-reflective on the interior
Screwed back with sapphire crystal glass
Crown double sealed
Waterproof, vacuum resistant and pressure resistant up to 10 bar

Dimensions and Weight

Case diameter: 42 mm
Band lug width: 20 mm
Lug to lug distance: 50.9 mm
Distance between the spring bars: 46 mm
Case thickness: 12.35 mm
Weight without strap: 67 grams

Watch configurator

No products have been found.

User manual

Download user manual for hand-wound watches (115.3 KiB)

Straps 20 mm

Leather Strap Arizona

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	190 mm	185 mm	191 mm	186 mm
ideal wrist circumference in inch	7.5 in	7.3 in	7.5 in	7.3 in
max. wrist circumference in mm	210 mm	205 mm	211 mm	206 mm
max. wrist circumference in inch	8.3 in	8.1 in	8.3 in	8.1 in
min. wrist circumference in mm	170 mm	165 mm	171 mm	166 mm
min. wrist circumference in inch	6.7 in	6.5 in	6.7 in	6.5 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Cordovan

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	189 mm	184 mm	190 mm	185 mm
ideal wrist circumference in inch	7.4 in	7.2 in	7.5 in	7.3 in
max. wrist circumference in mm	209 mm	204 mm	210 mm	205 mm
max. wrist circumference in inch	8.2 in	8.0 in	8.3 in	8.1 in
min. wrist circumference in mm	166 mm	161 mm	167 mm	162 mm
min. wrist circumference in inch	6.5 in	6.3 in	6.6 in	6.4 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Monza

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	185 mm	180 mm	186 mm	181 mm
ideal wrist circumference in inch	7.3 in	7.1 in	7.3 in	7.1 in
max. wrist circumference in mm	205 mm	200 mm	206 mm	201 mm
max. wrist circumference in inch	8.1 in	7.9 in	8.1 in	7.9 in
min. wrist circumference in mm	167 mm	162 mm	168 mm	163 mm
min. wrist circumference in inch	6.6 in	6.4 in	6.6 in	6.4 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Rally

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	185 mm	180 mm	186 mm	181 mm
ideal wrist circumference in inch	7.3 in	7.1 in	7.3 in	7.1 in
max. wrist circumference in mm	205 mm	200 mm	206 mm	201 mm
max. wrist circumference in inch	8.1 in	7.9 in	8.1 in	7.9 in
min. wrist circumference in mm	167 mm	162 mm	168 mm	163 mm
min. wrist circumference in inch	6.6 in	6.4 in	6.6 in	6.4 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Rotte

High-quality watch strap made of anthracite-colored wild boar leather.
Available with a pin or folding clasp.

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	183 mm	178 mm	184 mm	179 mm
ideal wrist circumference in inch	7.2 in	7.0 in	7.2 in	7.0 in
max. wrist circumference in mm	203 mm	198 mm	204 mm	199 mm
max. wrist circumference in inch	8.0 in	7.8 in	8.0 in	7.8 in
min. wrist circumference in mm	160 mm	155 mm	161 mm	156 mm
min. wrist circumference in inch	6.3 in	6.1 in	6.3 in	6.1 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Rotte XL

High-quality watch strap made of anthracite-colored wild boar leather in XL length.
Available with a pin or folding clasp.

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	192 mm	187 mm	193 mm	188 mm
ideal wrist circumference in inch	7.6 in	7.4 in	7.6 in	7.4 in
max. wrist circumference in mm	223 mm	218 mm	224 mm	219 mm
max. wrist circumference in inch	8.8 in	8.6 in	8.8 in	8.6 in
min. wrist circumference in mm	161 mm	156 mm	162 mm	157 mm
min. wrist circumference in inch	6.3 in	6.1 in	6.4 in	6.2 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Chronissimo (normal length)

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	213 mm	208 mm	214 mm	209 mm
ideal wrist circumference in inch	8.4 in	8.2 in	8.4 in	8.2 in
max. wrist circumference in mm	232 mm	227 mm	233 mm	228 mm
max. wrist circumference in inch	9.1 in	8.9 in	9.1 in	8.9 in
min. wrist circumference in mm	192 mm	187 mm	193 mm	188 mm
min. wrist circumference in inch	7.6 in	7.4 in	7.6 in	7.4 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Chronissimo (short length)

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	197 mm	192 mm	198 mm	193 mm
ideal wrist circumference in inch	7.8 in	7.6 in	7.8 in	7.6 in
max. wrist circumference in mm	216 mm	211 mm	217 mm	212 mm
max. wrist circumference in inch	8.5 in	8.3 in	8.5 in	8.3 in
min. wrist circumference in mm	174 mm	169 mm	175 mm	170 mm
min. wrist circumference in inch	6.9 in	6.7 in	6.9 in	6.7 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Antique

Leather Strap Antikleder — Pull up leather with laquered edging and colored stitch.
Available with a pin or folding clasp.

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	191 mm	186 mm	192 mm	187 mm
ideal wrist circumference in inch	7.5 in	7.3 in	7.6 in	7.4 in
max. wrist circumference in mm	210 mm	205 mm	211 mm	206 mm
max. wrist circumference in inch	8.3 in	8.1 in	8.3 in	8.1 in
min. wrist circumference in mm	170 mm	165 mm	171 mm	166 mm
min. wrist circumference in inch	6.7 in	6.5 in	6.7 in	6.5 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Leather Strap Vintage Brown

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	190 mm	185 mm	191 mm	186 mm
ideal wrist circumference in inch	7.5 in	7.3 in	7.5 in	7.3 in
max. wrist circumference in mm	210 mm	205 mm	211 mm	206 mm
max. wrist circumference in inch	8.3 in	8.1 in	8.3 in	8.1 in
min. wrist circumference in mm	178 mm	173 mm	179 mm	174 mm
min. wrist circumference in inch	7.0 in	6.8 in	7.0 in	6.9 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Rubber Strap Glatt

Black rubber strap, smooth surface,
incl. a laser engraved folding-clasp satinated or bead-blasted

Textile Strap Safety Belt

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	187.5 mm	182.5 mm	188.5 mm	183.5 mm
ideal wrist circumference in inch	7.4 in	7.2 in	7.4 in	7.2 in
max. wrist circumference in mm	208 mm	203 mm	209 mm	204 mm
max. wrist circumference in inch	8.2 in	8.0 in	8.2 in	8.0 in
min. wrist circumference in mm	167 mm	162 mm	168 mm	163 mm
min. wrist circumference in inch	6.6 in	6.4 in	6.6 in	6.4 in

Wrist circumference specifications are approx. values and depend on the individual wearing habits.

Silicone Strap S60

Cases 20 mm	Type 40	Type 60	Type 31	Type 155
ideal wrist circumference in mm	191 mm	186 mm	192 mm	187 mm
ideal wrist circumference in inch	7.5 in	7.3 in	7.6 in	7.4 in
max. wrist circumference in mm	213 mm	208 mm	214 mm	209 mm
max. wrist circumference in inch	8.4 in	8.2 in	8.4 in	8.2 in
min. wrist circumference in mm	172 mm	167 mm	173 mm	168 mm
min. wrist circumference in inch	6.8 in	6.6 in	6.8 in	6.6 in