Soft Plastic Crab Mold Soft Bait 3 Inch Bugmolds USA - 1 Cavity Mold. Bugmolds USA offers a high quality stone mold for 3in saltwater crab type soft baits. This mold is a single cavity piece that produces one soft lure that will be good for a lot of sea and ocean fish.We recommend using lubrication for our stone molds and an injector size for this cast mold of 5/8in. Create a large variety of soft plastic baits in colors of your choosing! Nothing better when you do it yourself. Great inexpensive durable molds that are compatible with plastisol. Free Shipping in the United States On All Bugmolds USA Products!