VSR ZERO Complete Upgrade Set with Steel Cylinder - Gen. 6

PACKAGE CONTENTS:

• ZERO Trigger Gen.6 (18036)
  The latest generation CNC-machined trigger mechanism featuring a 90° piston sear. Includes the new Sear Engagement Adjustment feature, an inspection window for visual verification, a trigger adjustable within a 7 mm range, a safety lever, and mounting screws.
• Lightweight ZERO Hybrid Piston (6720)
  Features an ultra-lightweight aluminum body, two polyacetal (POM) guide rings for smooth operation inside the cylinder, and a stainless steel piston catch.
• Stainless Steel Spring Guide with Thrust Bearing (6724)
  Equipped with a high-quality ball bearing to reduce friction and prevent spring twisting during compression.
• 9mm Upgrade Spring of Your Choice
  Manufactured from high-quality spring steel with proper heat treatment and ground ends. The surface is protected by black oxide coating. Available spring strengths range from M120 to M170.
• Steel Upgrade Cylinder (1858)
  Manufactured from seamless steel tubing with an inserted steel handle support. Both parts are securely welded together at four points and subsequently polished for smooth operation. The surface is protected by an industrial black oxide finish. The cylinder was designed for long-term use with powerful springs, where standard cylinders often fail due to deformation or bolt handle pull-out.
• ROUNDED Stainless Steel Cylinder Head (11112)
  Precision-machined from a single piece of stainless steel. Dual sealing ensures maximum utilization of compressed air. The integrated impact pad cushions piston impacts and extends the service life of the entire assembly. The rounded nozzle profile improves alignment with the hop-up bucking and optimizes airflow into the chamber.

SEAR ENGAGEMENT ADJUSTMENT

The sixth generation ZERO Trigger allows adjustment of the engagement depth between the piston sear and the trigger mechanism. By turning the adjustment screw, the overlap of the engagement surfaces can be changed, directly affecting the trigger characteristics.

• SAFE – larger sear overlap providing the highest safety margin.
• SPORT – balanced setting offering a compromise between safety and a shorter trigger pull.
• RISK – minimal sear overlap. Provides the shortest trigger pull but significantly reduces the safety margin of the mechanism.

Unlike most conventional trigger units, the engagement setting can be visually inspected without disassembling the mechanism through the inspection window located on the top side of the housing.

Warning: Make adjustments only in small increments and thoroughly verify safe operation after every adjustment. Excessively small sear engagement may result in unintended piston release caused by impact, vibration, or forceful bolt closure.

WHY THIS SET?

Many upgrade builds combine components from different manufacturers. While individual parts may be of high quality, their compatibility is not always guaranteed.

This set contains all key components of the cylinder and trigger assembly designed by AirsoftPro as a complete system. This eliminates compatibility concerns while providing maximum reliability and performance.

Compared to the standard ZERO Complete Upgrade Set, this version additionally includes a reinforced steel cylinder and a stainless steel cylinder head. The most heavily stressed components of the system are therefore replaced with durable CNC-machined parts designed for long-term use with powerful springs.

The result is an exceptionally robust upgrade package suitable for demanding users seeking maximum durability, superior air seal, and reliable operation even when using high-power springs.