Helium release valve. It is integrated in the watch case spring-loaded one-way valve activated when the difference between the inner and the outside pressure reaches a critical level. This function is useful for commercial divers operating at great depths using diving bells with breathing gas mix inside.
An enhanced hardened 3.5 mm thick mineral K1 crystal
Exhibition case back
18 Swiss-made tritium tubes: 13 pcs. in indexes-reflectors on the dial, 4pcs. on 3 hands and one in sapphire capsule in bezel.
Custom leather and silicon straps interchangeable by just one screw driver.
Whole watch set is packed to the original XL-size dry box . The dry box can be easily transformed to Collector’s Box with cells for storage of 4 watches, 4 additional straps and one screw driver