Check the listing for details. Fiber Optic Polymer Flip Up Folding Auto Deploy Front & Rear BUIS Back Up Sight. Condition: New. Listed at 16.99 USD. -Visible Front Red Dot Sight and Rear Green Dot Sight provide the brightest aiming points in low-light conditions.-Push Button Automatic Deploy Flip-Up Front and Rear Sight Towers Complete with A2 Square Post Assembly with Locking Retention and -Precision Elevation Adjustments for Greater Accuracy. -Mounting Decks Designed to be Used with Handguard & Flattop Rails and Both Will Fit All 1913 7/8" Picatinny/Weaver Style Rails. -Automatic Flip Up Deploy Button Release At The Push Of A Finger And Locks In Place When Deployed Or Folded.-Easy Quick And Secure Installation -Allen Screw Locking Clamp Rail Base Retention For Maintaning Zero Under Heavy Conditions.-Solid Reinforced Polymer Construction. Lightweight & Built To Withstand All Conditions, Designed for Shooters-Front Red Dot Sight and Rear Green Dot Sight -Fits: Picatinny/Weaver rails-Weight: 2 oz