Top Outlet Non API (Standard Conn.)  Top - Premium     2-3/8" K. Fox / Vam Ace     2-7/8" K. Fox / Vam Ace     3-1/2" K. Fox / Vam Ace     4-1/2" K. Fox / Vam Ace     5” K. Fox / Vam Ace     6-5/8" 15M Standard / Premium Connections  Side - Premium     2-3/8" K. Fox / Vam Ace     2-7/8" K. Fox / Vam Ace     3-1/2" K. Fox / Vam Ace     4-1/2" K. Fox / Vam Ace     5” K. Fox / Vam Ace     6-5/8" 15M Standard / Premium Connections  Tubing & Rotary     2-7/8" & Smaller     3-1/2" & Smaller     4-1/2" & Smaller (Standard)     4-1/2" & Smaller K. Fox / Vam Ace (Premium)     5-1/2” X –over (Full Hole - Standard)  Cross-Over - Vam Ace, TC4S, Vam, TDS, Standard / Premium Connections Fox (3-1/2" & Smaller) Premium Thread "RA" Subs