4 Post Design – Four 2.8mm Holes! 304 Stainless Steel Stainless Steel Dual Hole Center Post Silver Plated Brass Contact Pin 22mm RDA 6mm Deep Juice Well Comes with 1 Blue and 1 Silver AFC Ring 3 Drip Tip Options including massive delrin and metal chuff style and regular 510 adapter Peek Insulators with Extras Included