Change the power of your AEG on the field in seconds!
The Variable Velocity Device or VVD is a set that includes a piston and piston head as well as an adjustment tool. The piston has head venting that can adjust to three different positions to alter the air flow to adjust the power generated. The piston installs into a normal gearbox and then the tool can be used to adjust the valve setting from outside the gun (via the barrel).
The piston is polymer but has metal (steel) full teeth and a metal piston head; the use of materials lends this piston for use in higher powered setups (over 400 FPS and high rates of fire).
This piston will install in to standard version 2 and 3 gearboxes but is not compatible with Tokyo Marui next-gen gearboxes (i.e. shock recoil) nor will it fit into PSG-1 gearboxes or extended cylinders.
The adjustment tool is made up of a hollow metal handle and a set of metal rods. The rods can screw together end-to-end to a total combination length of 700mm. Of course you only have to use as much length as you need. Each segment has a small hole running through it which can be used with a small Allen key to get much better torque grip on it to tighten and loosen the components. The valve on the VVD piston is rather tight so the tool has to be screwed together tightly to may adjustment easier. Similarly, the tool will likely need a pair of small Allen tools to loosen if the rods are screwed together more than finger tight.