The Accu-Strike Series sights utilize Lightweight / compact design (weighs 5 ounces). TRU•FLO™ fiber design. Extra, extra long fibers routed through bracket for increased durability & exposure to UV light. TRU•TOUCH™ soft-feel technical coating. Innovative pin design allows for quick and easy fiber replacement. Micro push-button light included. Special light location allows for more effective light distribution to fibers. CNC-machined. Aperture has 1.8” inner diameter.