This jet from the CMP Typhoon 400 series needs to be clipped into the corresponding socket. It is part of the "Crown" range, with a grey and stainless steel plastic front panel.
It is found on many spas, including some Sundance spas known as DVX.
Careful! These jets look a lot like Waterway's Poly Storm jet, but they are not compatible.
Overall length: 112 mm
Diameter of the jet face: 104 mm
Length of the jet back: 90 mm
Provides a powerful, adjustable massage jet from a relatively wide opening