This bipod mounts on handguard rail. Folds back when not in use! Metal construction! Adjustable leg length.

AR Bayonet Lug Bipod Quick Release
Specifications
-AR/M16 Bipod attaches to most Bayonet Lugs
-Weight:12.5 oz.
-Height:6.89" (Legs collapsed), 9.53" (Legs extended)