Comparison : Item # 8059-24, Tube with Cap, Dual Purpose, All-Glass, Size 21, 15-415 GPI Thread
Item # 8059-26, Tube with Cap, Dual Purpose, All-Glass, Size 22, 18-415 GPI Thread
Item # 8059-28, Tube with Cap, Dual Purpose, All-Glass, Size 23, 24-215 GPI Thread