The UTG Pro Receiver Extension Tube is a 6-position Mil-spec diameter receiver extension tube for AR-15 rifles. It is CNC Machined from 6061-T6 Aircraft Grade Aluminum with Precisely Rolled Threads for Durable Thread Engagement with Lower Receiver.

Features :

• Black finish
• Tightest Tolerance Control for Zero-gap Fit
• Fits Any standard AR-15 lower and a Mil-Spec diameter collapsible stock (not included)