This set of Support Cones sit above the rubber feet and will fit the following bipods:
HD-50
FC-10
FC-4 G2
FC-5 G2
WB-5
WB-4
PC-5
PC-4
LR-10
LR-10 QD
LR-10 G2
SR-5 G2
BR-4 G2
All Arca model bipods.