A medical device includes a distal portion sized and shaped for insertion into a body lumen and including a capsule having a lumen extending therethrough and a plurality of windows in a proximal end thereof a bushing including a channel extending therethrough, a distal end thereof including a plurality of arms extending distally therefrom such that a corresponding one of the arms is releasably engagable with a corresponding one of the windows of the capsule, the arms being biased toward a centerline of the bushing in a release configuration and a bushing support receivable within the channel of the bushing to apply a radially outward pressure to the arms such that the arms lockingly engage the windows of the capsule, the arms formed of a material selected such that movement of the bushing support out of the channel reverts the arms to the release configuration.