Mini HPA tanks, good for air stocks like the UGS, Aero, Redline, or Mancraft offerings. Also good for things like a VSR-10, FAMAS, or M82 Barrett for going inside a gun. 5/8-18 standard HPA/paintball/airsoft threading for Ninja, Tippmann, Empire regs etc Working pressure of 5,000 PSI, can be used below but at the cost of less shots Compatible with real steel and airsoft spec M4/AR stocks Custom lengths available