Aluminum Cam & Groove Adapter, Female Half, 4x3 Inch Reducer

Those cast-in lugs on the female coupler let you run a safety pin through once the adapter is seated and the cam levers are pressed down. Until that pin gets pulled out, the coupler won't release. So it's not just a passive backup, it's a deliberate lock that has to be manually removed before anyone can uncouple it. Good feature to have on lines you don't want coming apart mid-operation.

These aluminum cam and groove reducers are rated to 150 PSI for the sizes 1/2" to 4". This 4x3 reducer falls within that range.

On interchangeability, it is built to the A-A-59326 standard (also noted as compatible with DIN 2828), so it will interchange with other cam and groove products made to those same standards.