Traxstech Fishing systems swivel base with riser for downriggers mounted to tracks for trolling fishing 3/4" thick aluminum top plate that is pre-drilled and tapped. 3/8" diameter stainless steel plunger; 12 available positions to swivel every 30 degrees All aluminum construction and stainless steel components Fits most popular brands - Cannon, Fishlander, Big Jon, Scotty, Penn & Walkers Shipped with Signature Required. Message Seller to waive requirement