Fiber battery washer set: It can prevent corrosion around the battery terminals, prolong battery life, for use with 6 and 12-volt battery Application: These battery terminal protectors can be used for top post batteries, side post batteries or cables. Flexible size: The inner ring can be removed to fit larger terminals. The outer ring diameter is . 46mm. The inner ring diameter is . 19mm. Diameter of the inner ring after removing is . 30 mm. Colors: The two different colors have been coded for positive and negative terminals. Red is for +,and green for -. Easy to distinguish and use Color: Red + Green Material: Felt Package Contents: 6 x Red Battery Terminal Anti Corrosion 6 x Green Battery Terminal Anti Corrosion Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.