LED tubes as Fluorescent tubes replacement, It will be 55% Energy Savings, No fluorescent paint and gas contamination of premises, Bypass Expensive Ballasts And Wire Direct.  The standard fluorescent tube of T6, T8, T9, T10, T12 have same base, Their base is G13, Their difference is the diameter of tube: The T6 tube is dia 21mm, The T8 tube is dia 26mm, The T9 tube is dia 31mm, The T10 tube is dia 34mm, The T12 tube is dia 38~40.5mm. So usually our T8 or T10 LED tube can as standard T6, T8, T9, T10, T12 fluorescent replacement.