Samson Aluminum Tubular Fids & Pushers are used to splice the most commonly used climbing and rigging lines in tree work. Each diameter of rope has a matching fid size and to insure that the required measurements are made correctly, the proper sized fid for the rope size must be used in performing a splice. Aluminum Tubular Fids are used by inserting the end rope section into the fid. Tubular fids are pushed through the rope with an appropriate sized pusher.