The Mechtech CCU (Carbine Conversion Unit) for Glock pistols accepts the complete Glock lower receiver — trigger group, magazine, and controls — to convert it into a 16.25-inch barrel carbine. The .45 ACP version uses Glock 21-compatible frames. No serialized parts change hands; only the lower is transferred. Type: Rifle Action: Semi-Automatic Caliber: 45 ACP Capacity: 10 Year introduced: 2001, USA Weight: 40 oz Overall length: 26" Status: Active Intended use: Home Defense, Range, Conversion