Prevent line twist with these affordable Snap Swivels. Swivel color Black. Snap swivels have a safety-pin like clip linked to one of the rings. Lures may be affixed directly to the snap. The presence of the swivel has been said to detract from the effectiveness of some types of lures. Depending on the position of the lure, the hooks can become entangled in various ways with the swivel. It is also noted that swivels can serve as weak points in the line, and therefore lessen the likelihood of landing larger or harder fighting fish.The main purpose of the swivel is to allow the line to untwist during line retrieval, preventing undesirable tangling. This is particularly important for users of monofilament test line. A secondary benefit of the fishing swivel is that it may stop a sliding sinker, which depending on fishing method may be placed before or after the swivel.