This is a 1/4" male stainless steel socket, also known as a quick connect coupler. This part is generally inserted into the outlet of a trigger to make the barrel of the gun quick connect or allow for direct foam cannon connection. (See image below)
Specifications
Material: Stainless Steel (303)
Size: 1/4" quick connect socket x 1/4"MNPT
O-Ring Material: EDPM (alkaline resistant)
Max Pressure: 5000 PSI
Max Temperature: 175 degree's (F)
Manufacturer: General Pump