Exactus Aquamax Safety Super-Compressor 41mm case.

The Super-Compressor Exactus Aquamax Safety case refers to a patented sealing method developed bywatch case manufacturer Ervin Piquerez. The design takes advantage of the water pressure. The case is exposed to at depth to press the case back against the o-ring seal. Consequently, more depth equals more water pressure equals greater seal.

The Exactus Aquamax Safety dual crowns at 2 and 4 o’clock. (one to set the time and the other to control the inner diver’s rotating bezel) feature a distinctive cross-hatch finishing, over which many brands placed their logo.

Along with the typical cross-hatch finishing on the crown. The case backs of Super Compressor divers often bore EPSA’s dive helmet logo.

The Exactus Aquamax Safety polygonal-shaped unique case back fits together with a bayonet attachment system, ensuring stripped or crossed threads. This quirky, yet efficient caseback design sets Exactus Aquamax Safety diver watches apart from the others, making it an excellent and sought-after vintage diver.

The brands full name was Montres Exactus SA, and they were based in Neuchatel, Switzerland. It would appear, like many other brands of the era, they were contracting out ready-made designs and re-branding them.