Rossi M4 Sentinal Zeta 8.5" Black

Construction & Aesthetics

• Hybrid Build: Features a polymer receiver blended with a CNC-machined M-LOK handguard - balancing lightness with rugged resilience

• Compact Profile: With its 8.5″ barrel, this CQB-oriented platform is short, nimble, and ideal for tight skirmish environments.

Internals & Performance

• Gearbox: Version 2 with an 18:1 steel gearset, steel-tooth piston (14.5 teeth), 8 mm bearing bushings, and a quick-change spring guide - supporting durability and maintenance ease

• Trigger System: ETU Ver.1 with an electronic active brake for crisp, responsive semi/full-auto fire control

• Barrel & Hop-Up: Precision 6.02 mm inner barrel housed within metal outer barrel; equipped with adjustable hop-up for trajectory tuning

• Velocity: Delivers roughly 300-320 fps using 0.20 g BBs - well-suited for UK field standards

Ergonomics & Handling

• Size & Weight: Compact and wieldy; length varies depending on stock type, and weight usually around 2.0-2.2 kg (without battery).

• Fire Selector: Features safe, semi, and full-auto modes for versatile engagement options

Ideal Use & Highlights

• CQB Specialist: Its 8.5″ barrel and lightweight construction make it an excellent pick for indoor or close-quarters play.

• Upgradeable Core: High-quality internal components and ETU electronics provide a strong platform for future upgrades, like mid-caps, optics, or suppressors.

• User-Friendly Maintenance: The quick-detach spring guide simplifies FPS adjustments and compliance with game rules or field limits.

Quick Specs Table

• Feature
  Specification
• Body
  Polymer receiver; CNC M-LOK handguard
• Gearbox & Gearing
  V2 gearbox, 18:1 steel gears, steel piston
• Bearings
  8 mm bushing
• Trigger System
  ETU Ver.1 with active brake
• Barrel Inner
  6.02 mm precision
• FPS
  ~300-320 fps (0.20 g)
• Fire Modes
  Safe / Semi / Full-auto
• Weight
  ~2.0-2.2 kg (no battery)
• Length
  Compact CQB length (~adjustable stock)

The Sentinel ZETA 8.5″ is a balanced, compact AEG combining lightweight handling, reliable internals, and modern modular features - all at an attractive price point. Whether you're focused on CQB performance or seeking a foundation for upgrades, this model is well-suited to both roles.