Sakuma 503 Bait Holder Hooks. 503 Bait Holder Hooks are ideal for use with softer baits such as mussel, worm and fish, due to the raised bait retaining barbs on the back of the shank. Available in sizes 8, 6, 4, 2, 1, 1/0, 2/0, 3/0 and 4/0.