The SI TECH Thetis Exhaust Valve is a low profile high performance valve suitable for all areas of recreational and technical diving. SI TECH Exhaust Valves are extremely sensitive to variations in pressure providing the diver with excellent buoyancy control and built in safety features that ensure no gas is released while on the surface. The construction of the filtered attachment nut makes the valve suitable for use in conjunction with all common undergarments.

• Manual or automatic venting, resistance is ratchet action adjustable with adequate flow
• Thetis total height is ~ 45 mm of which the lower part attachment nut is ~17 mm and the upper part exhaust valve is ~28 mm; total width is ~ 69 mm with large guide ridge.
• Diameter of the mounting hole is ~ 33 mm. (FYI, the SI TECH valves are NOT compatible with Apeks valve ports; the Apeks mounting hole has a diameter of ~ 37 mm.)
• Due to the thread length on the valve, we recommend limiting installation of this valve to material thicknesses not exceeding 5 mm.
• Construction is thermoplastic alloy of amorphous polycarbonate and semi-crystalline polyester (PC/PBT) material.

FYI - The internals, functionality, and operation of the three different SI TECH exhaust valve models are identical and are interchangeable. The SI TECH Thetis, Arg, and Gaude exhaust valves differ only in the cosmetic appearance of the cap. Different drysuit manufacturers simply prefer the cosmetics of a specific model exhaust valve as one of the differentiators for their brand.