TruGlo's Brite-Site Fiber Optic sight set uses traditional fiber optics for bright aiming points, even in low-light conditions, and the Tri-Dot aiming system of contrasting front and rear colors. It utilize CNC-machined steel construction, concealing the fibers so they cannot be seen by your target, and have Truglo's Fortress finish for a permanent protective coating and maximum protection. It has a snag-resistant design and fit standard holsters. This model is compatible with Glock 17/17L/19/22/23/24/26/27/ 33/34/35/38/39 (excluding MOS models).