'F' Marked Front Sight Base (FSB)
The 'F' marked Front Sight Base (FSB) is intended to be used with flat top receivers, which require a slightly taller FSB. These are new and undrilled. They should be installed by a qualified gunsmith using taper pins or dowel pins. Made in the USA!
This is the Front Sight Base ONLY. Does NOT include sight post, spring, plunger or sling swivel assembly.