Whatever is on there, make your life easy going forward and change them to the standard for mini diggers. Flat face couplings, Holmbury are the best make. All you will need to do is identify the thread in the back of your couplers (maybe 3/8 BSP but this could be the tricky part). Then buy a pair of the flat face to suit, and anything you buy or hire will generally come with flat face.
Flat face couplings are in various diameters, DN06 is normal for mini diggers, maybe dn08 on 2.7t upwards. Here is an example, don't buy this. Flowfit are brill for most things but their couplers are s**t.
Hydraulic flat face quick release couplings Female 3/8" BSP, DN06, ISO 10, 350 Bar rated, 23 L/min.
www.flowfitonline.com