The primary purpose of an overpressure release valve is to prevent accidental over inflation of your BCD or drysuit by automatically releasing extra air contained in the bladder once it reaches a critical point.

This overpressure release valve is sold as a complete set allowing you to fit it yourself onto your BCD or dry suit. It also comes with a 12 cm long (4.75 inches) string attached to it, enabling you to trigger the dump valve yourself should you need to quickly release air from your BCD or dry suit. This overpressure release valve is of a simple design making it easy for you to assemble and fit onto your equipment. It includes the internal mushroom bolt, a double layer seal, the outer nut, a stainless steel spring, and the overpressure release valve with a string attached to it.

This valve will fit in a 3cm (1.18 inches) diameter hole and has an external diameter of 5cm (2inches).