Product Description The Radian Weapons Model 1 Complete Upper (R0903) is a premium AR platform upper assembly built for shooters who want high-end materials, precise machining, and a ready-to-run configuration. Chambered in 6mm ARC (Advanced Rifle Cartridge) with an 18 inch barrel and a durable black nitride finish, this complete upper is designed to deliver excellent accuracy potential and corrosion resistance. It features a modern free-float handguard with Magpul M-LOK mounting slots for accessories, plus a direct-impingement gas system for familiar AR reliability and parts compatibility. Product Highlights 18 inch 6mm ARC barrel with black nitride finish for wear and corrosion resistance Billet-machined 7075-T6 aluminum upper receiver with M4 feed ramps Free-float handguard with Magpul M-LOK modular mounting and anti-rotation design Rifle-length gas system and 5/8x24 muzzle threads for compatible muzzle devices and suppressor setups Designed to provide sub-MOA accuracy potential with match-grade ammunition (per manufacturer listing details) Specs Brand: Radian Weapons Model/Series: Model 1 Complete Upper MPN: R0903 UPC: 810098420952 Caliber: 6mm ARC Barrel Length: 18 in Barrel Material: Steel (listed as 416R stainless steel on some product listings) Barrel Finish: Black Nitride Upper Receiver Material: 7075-T6 Aluminum Handguard Interface: M-LOK Gas System: Direct Impingement, Rifle Length Twist Rate: 1:7 Muzzle Threads: 5/8x24 Weight: 5.97 lb (listed) Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the products manufacturer.