Replacement front sights work in conjunction with factory rear sights to give you fast sight acquisition in most light conditions. Machined steel body uses overmolded technology to completely cover and protect the light gathering, polymer LightPipe with an extra layer of clear polymer. Gunsmith fitting recommended.S&W CLASSIC, PERFORMANCE CENTER & DX MODELS -Interchangeable for different shooting distances and scenarios. Easy-to-see, bright red or green light rod makes target acquisition fast and efficient. Specially machined base is precision cut to fit factory ramp or base. Fits S&W Classic, Performance Center, and DX models. SPECS: Steel, black, matte finish. .813' (20.6mm) long. Available in .208', .250', and .310' heights.