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ProTek's Aggressor Series 4000 is a 45mm tritium diver, 300m, US$575

ProTek's new diver runs Swiss Pro-Glo T100 tritium in a 45mm carbon composite case, good for 300 metres and US$575.

Hen & Mills Editorial · 2 min read · 7 August 2026

ProTek Aggressor Series 4000 carbon composite dive watch — Image: ProTek Watches

ProTek says the tritium in its new Aggressor Series 4000 will still be glowing 25 years from now, and it asks nothing of you in between. Ordinary lume has to be fed. Leave a watch in a drawer overnight and by morning there is nothing left in it. Tubes make their own light, so there is no charging and no parking it under a lamp before bed.

The grade is Swiss Pro-Glo T100, and the T100 is the part worth noting. Tritium comes in brightness classes and T100 is the top of what you get in ordinary civilian kit. ProTek puts it at roughly 100 times the output of standard photoluminescent lume.

The ProTek Aggressor dial in darkness, its hour markers glowing blue with green markers at the quarters and orange at twelve — Pro-Glo T100 tubes, self-powered and colour-coded. Image: ProTek Watches

Black, blue, orange and yellow

The watch doing the glowing is US$575, knocked down to 550 as we write. Four references, four dial colours: PT4001 black, PT4003 blue, PT4004 orange and PT4007 yellow. The blue, yellow and orange straps are also sold separately, so the colour you order is not the colour you are stuck with.

The ProTek Aggressor worn on a wrist beside the sea, next to a dive mask — Eighty-two grams, which is light for a 45mm watch. Image: ProTek Watches

Carbon case, sapphire crystal, 300 metres

The case is carbon composite, 45mm, with a 60-click unidirectional ratcheting bezel. Crown and caseback are both 316L steel and both screw in. The crown carries multiple O-rings and is matched to the dial colour. Water resistance is 300 metres, and ProTek tests every watch in air and in water, which is more than plenty of brands bother with.

The crystal is sapphire with an anti-reflective coating. Not what you would guess at this money on a case this size, and it did not turn up in the early write-ups.

All of it weighs 82 grams, which is nothing for a 45mm watch and entirely down to the composite. The strap is rubber, 22mm tapering to 20, on a steel signature buckle with quick-release pins.

The 316L steel screw-in caseback. Image: ProTek Watches

One battery every four years

Inside is the Citizen/Miyota 2035 quartz, three hands, four-year battery. Put that next to the tubes and the upkeep you are signing on for is a battery swap once a presidential term. No winding, no charging, no regulating.

The 2035 is about as basic as quartz gets, and it is fair to say so. It keeps good time, it costs almost nothing, and nobody has ever admired one. On a 575-dollar watch built around its lume and its case material, that is exactly where the money should not go, but if you want something to stare at through a caseback, this is not it.

Whether 45mm fits you

Forty-five millimetres will settle this for most wrists before anything else gets a hearing. If it does fit, the rest lines up nicely: quartz, a four-year battery, and lume that keeps going for a quarter of a century. Leave it in a drawer for ten years, pick it up in the dark and you can still read the time off it. Not many watches at any price manage that.