1.Tube Protector for 12AX7, 6N3 2.Tube Protector gold plated 3.Tube Protector brass 4.Tube Protector high quality Silver Tube Guard Protector PreAmp 12AX7 12AU7 6922 5687 ECC Small: brassfor 12AX7, 6N3 etc.out diameter:40mminside diameter:26mmheight: 43mmthickness: 2mmsilver plated Silver Tube Guard Protector PreAmp 12AX7 12AU7 6922 5687 ECC,