b'Plan-A Adapter ( 1.375x24 ) Plan-A 1.125x28 Adapter Optimus Micro Taper Mount InterfaceMSRP: $89.95 MSRP: $89.95 MSRP: $89.95Plan-A XL ( 1.375x24 ) Taper Mount Thread Protector Taper Mount Direct Thread AdaptersMSRP: $89.95 MSRP: $16.99 MSRP: $89.95137'