Caterpillar OEM 150-3034 or 129-1555 Check Valve - New
Fluid Line Products (FLP)   

Relief Pressure setting 760 kPa (+-70) at 20 L/min

This listing is for 1 Check Valve

Cat List $396.85

Also  129-1555 is same part but without orings included
pic 2013-3-12 001 58,9 39pc 

I have a large inventory of hydraulic connectors not yet listed, ask me.