1.Tube Protector for 300B, 2A3 2.Tube Protector gold plated 3.Tube Protector brass 4.Tube Protector high quality Gold Plated Tube Protector for EL34, 6L6Large: brassfor 300B, 2A3 etc.out diameter: 90mminner diameter: 68mmheight:130mmthickness: 2mmgold plated Gold Plated Tube guard for 300B, 2A3 etc