Abstract: A holster for a bow string release or other tool comprises a base mountable on the inner forearm of a user and an elongate carrier pivotally connected to the base for free swinging movement from a position overlying the base and the user's forearm to a position projecting forward from the base along the user's hand. The free end of the carrier carries the bow string release. The base and the carrier have inter-engageable latches for releaseably retaining the carrier in a stowed position overlying the base, and an actuator has a portion projecting laterally for selectively releasing the latches. A load bearing strap is attached to the carrier on an outer portion thereof, which can telescope with respect to an inner portion.