An adjustable strap holder comprises a housing having an end face and a channel that extends from the end face axially into the housing. The adjustable strap holder also comprises an extension rod or bar that extends into the channel of the housing so as to have an exposed end that extends from the end face and a strap button secured to the exposed end of the extension rod. Further, the adjustable strap holder comprises a release mechanism coupled to the channel, where the release mechanism is operated by a user so as to allow the extension rod to be adjusted axially relative to the end face and/or removed from the instrument body.