HPA conversion kit for Bolt Action sniper rifles. Compatible with VSR 10 models and the Echo1 M28. Testing is in process for other sniper models as well. A few technical highlights from the BOLT: Electro pneumatic: This means there will be a small battery, but NOFCU. The trigger simply attaches to the outside of the trigger box andis actuated by the trigger. When actuated it powers the valve and firesthe bb. This means the consistent output of a solenoid without thecomplexity and battery drain of an FCU. Exclusive 3-way valve design created by Wolverine Airsoft andmanufactured by MAC powers the system. NO MOVING PARTS: During the firing of the bb nothing in the systemmoves other than the Solenoid Valve opening. Patent Pending Air Saver™ Technology: Allows you tosimultaneously save up to 50% of your air per shot and match the volumeair output of the system to the barrel. Optional 1 Piece aluminium bolt simplifies the installation especially on guns where the cylinder head is pinned to the cylinder. Will have the option of using a special version of our BOLT for self-contained co2 cartridge use with no external air line. ~150 shots per cartridge is possible even at 2+Joules! Input pressure(subject to change): 80-180psi. Output Energy: 1-4+J depending on setup and bbs used