Singe Locking Release Valve from Palfinger.  Part number P-67282345. 

This is commonly found on the Minifix, ILK, ILP, ILR.  For convenience, we have supplied, the breakdown for each of these models below in case the surrounding parts are needed.  Scroll through the product pictures or view the gallery to see these break downs.

If this is for an ILD, click here for the full power unit break down.