The STT-15L has all the same great aesthetics as our standard STT-15 Receiver Combo but incorporates a significant weight reduction. We set out to design our STT-15L for those who participate in 3-gun hunting or any other shooting activity where weight is a concern. - The STT-15L Lower weighs 7.7oz and accepts all Mil-Spec AR-15M16 components and lower parts kits excluding the ambidextrous controls. The STT-15L Upper weighs 6.9oz and works with all Mil-Spec AR-15M16 components including all known handguard options currently available. - Features: - A True Hand Matched Receiver Set With The Upper Serialized To Match The Lower Serial Number. - Huge 1.38" Integrally Machined Magazine Well Flare. - Short Throw Bullet Pictogram Safety Selector Markings Marked. - Set Screw Trigger Creep Adjustment. - Set Screw Upper Take Down Tension Adjustment. - Captured Rear Take Down Pin Detent And Spring. - Oversized Winter Trigger Guard. - No Roll Pin Design Assembles Using Included Threaded Dowel Screw. - San Tan Tactical Pillar Truss Pockets For Increased Structural Rigidity. - Cut From A Single Billet Of 7075 -T651 Aerospace Grade Aluminum. - Shell Deflector - Machined In T Markings For Easy Optic Relocation. - Machined With M4 Feed Ramps. - Machined To Mil-Spec Standards. - Interfaces With All AR15/M16/M4 Weapons Systems And Accessories. - Accepts ALL Known Handguards Without Modifications. - Mil-Spec Type III Class II Hard Coat Anodized Black - Ultra Light Design. Ultra Strong Yet Lite Weight. Weighing Only 14.6 Ounces / 413.9 Grams For The Matched Set. - Backed By STT's Unmatched Lifetime Warranty. - Made in the USA! - Does Not Include STT Ultra Grip Kit (Bolt Catch & Extended Magazine Release) Or Port Door Assembly