Very well made and finished lightweight alloy oleo strut with offset, it is sprung loaded and will accept a wheel of up to 70mm (2.75ins) diameter.
Length to Axle Center: 108mm
Max Wheel Size: 70mm (2.75ins)
Retract Mounting Pin: 5mm (not included)
Axle Diameter: 4mm
Installed a set of these on a VQ Models Ki-61, which is the same model that HK sells. Fit very well with the aid of some 5mm motor shafts cut down to the proper length to attach to electric retracts. Lost one of the grub screws that holds the axle in place and had to replace it, which is 4mm if anyone needs to replace one.