Similar to the basic design of the ARP-38 but instead of having the lug beneath, this has an insert adaptor that fits inside the vertical leg and is held in place by an appropriate adhesive, rivet or screw. The rail fits on to an adjustable cupped bracket and once the desired angle has been achieved, there is a provision to lock off that angle on the stem of the support bracket by allen key fixing. It has two fixing holes on the diagonal axis.

The initial streamlined model requires the rail to fit flush with the top of the insert adaptor.  An alternative product with a tube hiding collar is a recent addition and is available now.  The two products remain identical other than that feature.