This is the famous Jinming Gen 8 Gearbox, it's full nylon made, reliable and durable. This is superior to the old one with metal bushings and nylon gears. But most importantly a harden nylon shell. Compatible with JinMing SCAR / JM Gen8 M4a1 / HLF UMP45 / JM MP5 / JM Gen13 / XM316 / blg m16 / ZH m249 and other gel blasters using gen8 gearbox. Features: • Full Nylon Construction — Hardened nylon shell, gears, trigger, T-piece and motor housing for superior durability over stock parts • Upgraded Over OEM — Metal bushings replaced with reinforced nylon for smoother operation and reduced wear under sustained fire. • Powerful 460 Motor Included — No sourcing extra parts; ready to install and run straight out of the box. • Two Fire Mode Options — Choose Original (full auto) or New (semi/full auto) to match your play style and blaster setup. • Broad Gen8 Platform Compatibility — Fits JM M4A1, SCAR, UMP45, MP5, Gen13, XM316, BLG M16, ZH M249 and more. • Drop-In Replacement — Designed to fit existing Gen8 housings with no modification required. • Extend Your Blaster's Life — Rebuild instead of replace; keep your favourite platform running at peak performance. Specifications: Brand: jin ming. Material: nylon constuction with nylon gears. Fire mode: full automatic (old), semi/full auto (new). Color: black. Motor type: 460. Plug type: sm. Package includes: 1x jm gen8 gearbox. Gen8 Gearbox Disassembly Videos: