As a leader in the field of firearms testing and training products, Dvorak Instruments is at the forefront of air recoil simulation technology. The Dvorak Tetherless Recoil System or TRS and the Dvorak Air Recoil System or ARS are drop in recoil simulators that quickly and easily convert semi-automatic and automatic firearms into safe and effective training tools. Using compressed CO2 gas, the systems simulate recoil by acting on the guns bolt or slide to "cycle" the gun. (less)