Retro Arms CZ Billet CNC 8mm Ver.2 Gearbox Shell for M4 Series Airsoft AEG Rifles
(Model: Split Gearbox / Hop-Up Chamber)

Features

• Precision machined from a block of billet EN AW 7075 T651 aluminum
• Split gearbox design allows easier installation of internal parts
• Includes Retro Arms CNC aluminum rotary hop-up unit
• Quick change spring guide system
• Durable anodized finish
• Reinforcement in key stress points to counter rapid wear from high performance parts
• Pre-radiused cylinder windows - helps evenly distribute impact force
• Deeper wire channels along base of gearbox

Unlike most other gearbox shells on the market, the Retro Arms CZ gearbox shells are precision CNC machined out of a solid block of billet EN AW 7075 T651 aluminum giving them unmatched durability and resilience. Combined with reinforcement of key stress points and stainless steel connecting bolts, the gearbox shell has undergone extensive stress tests with M160 springs without any signs of wear.

Version 2 Retro Arms gearboxes feature a quick-change ball-bearing spring guide mechanism, allowing spring swaps in a matter of minutes without complete gearbox disassembly.
Split gearbox means that this gearbox is designed to have a two part upper and lower. An advantages of having a split gearbox is that it's much easier to install internal parts into the gearbox. During setup of a cylinder set, there is no need to remove the whole gearbox from the receiver and only the upper part needs to be removed as it's mounted on the receiver pin.

Manufacturer: Retro Arms CZ

Disclaimer: Please use discretion when installing custom parts as fit and compatibility may vary. Some modification may be required. Professional installation recommended.