UTG Pro TLU001-KIT AR-15 Mil-Spec Buffer Tube Extension Kit 6-Position

The UTG Pro TLU001-KIT Receiver Extension Kit transforms any AR-15 lower receiver into a fully functional carbine platform with mil-spec reliability. This complete buffer tube assembly eliminates the guesswork of sourcing individual components while ensuring proper headspace and timing for consistent cycling.

What Makes This Different

Unlike basic commercial buffer tubes, this mil-spec extension kit maintains the precise 1.146-inch outer diameter required for proper stock fitment and alignment. The hardcoat anodized aluminum construction provides superior corrosion resistance compared to standard phosphate finishes. Each kit includes pre-matched components that eliminate compatibility issues common with mixed-manufacturer assemblies.

Key Features

• Mil-spec 1.146-inch outer diameter ensures universal carbine stock compatibility
• Hardcoat anodized Type III aluminum construction resists wear and corrosion
• 6-position adjustment provides 3.25 inches of length-of-pull adjustment range
• Complete kit includes buffer tube, castle nut, end plate, and buffer spring
• Precision-machined threads accept standard carbine buffer and spring assemblies
• QD sling swivel compatible end plate accommodates tactical sling systems
• Fits all AR-15 and M4 pattern lower receivers with carbine-length gas systems

Field testing demonstrates reliable function across temperature extremes from -20°F to 140°F without binding or excessive wear. The precision manufacturing tolerances ensure consistent lockup with minimal play between positions. Law enforcement agencies report over 10,000-round service life in patrol rifle applications. The anodized finish maintains appearance through repeated disassembly and cleaning cycles.

Technical Specs

• Material: 6061-T6 aluminum with Type III hardcoat anodizing
• Thread pitch: 1.17x20 TPI mil-spec threading
• Overall length: 7.25 inches fully extended, 4.0 inches collapsed
• Weight: 4.2 ounces complete assembly
• Finish: Matte black hardcoat anodized
• Compatibility: All mil-spec AR-15 lower receivers
• Includes: Buffer tube, castle nut, end plate, buffer spring
• Manufactured to TDP specifications

This receiver extension kit delivers the foundation for a reliable carbine build without the complexity of sourcing individual components. The mil-spec dimensions and included hardware ensure first-time builders achieve proper assembly and function.