The TechT Low Pressure Spring Kit allows players to modify the bolt return spring in their Tippmann TPX Pistol. The kit of three different strength springs, each allowing the user to vary the markers operating pressure to use less pressure, makes the marker easier on brittle paint, and can yield more shots per 12 gram CO2 cartridge. The springs also allow the marker to slowly loose velocity after each shot when running low on CO2 rather than having a sharp drop off in pressure. This drop in velocity gives you warning that you are running low on CO2