The Twister Track Knob is offered in 5 different color options and has an overmolded stainless steel insert to combat corosion in fresh or saltwater applications. The outer base is outfitted with several groves to give you some extra grip to get snugged down. You can also grab onto the twister wings on top of the knob to torque the knob down & get the tightest fit posssible. The wings also protect the shaft of the bolt as well as preventing snagging lose lines. The Twister Track Knob is made in the USA and uses high quality material to insure dependable operation. Many fine details were added to this design to provide more grip and easier use than other knobs on the market.