Black Spider LLC Low Red Dot Sight Fits Picatinny Center Dot with Lens Covers The M0129 Micro Red Dot Optic is the first of its kind to provide a high-quality optic with a rugged, durable mount, all while being specially designed for AR-15 Picatinny rails Length: 2.86 in. Center Height: 38.5mm. Weight: 6.6 oz Push button controls and auto-dimming features make it easier to transition to low light environments