Add function to push button swivel bases with the ingenious Multi-Adaptor. Use supplied allen wrench to Depress plunger and slide into base. Standard stud is ready to accept all swivel types and/or mounting of bipods and accessories that require standard studs. Fits all standard push button swivel bases. Includes:- two multi-adaptors - two stainless steel bases. Specifications:- fits: all standard push button swivel bases- finish: black-oxide.