A downhole arrangement (32) comprises first (34) and second (41) members, a lock profile (4) fixed relative to one of the first and second members, and a lock member (10) for engaging the at least one lock profile. A release member (40) is provided which is moveable to selectively lock the lock member in engagement with the lock profile so as to selectively secure the second member relative to the first member. Such a downhole arrangement may permit a releasable connection between the first and second members.