The Evolution Holster is a passive retention holster that includes a retention adjustment screw. The tension screw is not pre-set and allows for retention pressure to be adjusted based upon personal preference. When un-holstering, do so in a deliberate and rapid upward motion. Passive retention is automatically engaged upon re-holstering. Designed for: Kimber Micro, Kimber Micro 9, Sig Sauer P238, P938 .22, P938 9mm, Springfield 911 .380 ACP.