Introducing the 7-Star T-Track Knob Kit by POWERTEC. This exclusive pack of 4 contains knobs, bolts and washers arranged together to help secure and enhance your woodworking jig and fixture assemblies. They are designed to offer a supplemental and long term clamping strategy to your projects and work seamlessly with any drill press, lathe or saw that accommodates a 5/16 in. -18 internal thread size (also most 3/4 in. W x 3/8 in. D t-tracks). [EXCEPTIONAL BUILD] : Each knob is made with Polypropylene, a heat resistant thermoplastic known for its toughness and durability. However, its most noticeable feature is the robust, ergonomic design that's smooth to touch and comfortable to handle - eliminating hand injuries caused by inferior quality and tiny, hard to turn wing nuts. In addition, we've chosen to use molded plasted steel inserts. In doing so, we've taken away the threat of stripping, while offering a helping hand in fighting corrosion or rust. These items may be simplistic in function, but our engineers have made sure that you'll actually feel the quality and craftsmanship that has gone into each knob.