Package: 24 pieces battery terminal anti corrosion washers include 12 red and 12 green, enough quantity for your use and replacement. Color: the color coded for positive and negative terminals, red for +, green for -, easy to distinguish and use. Flexible size: inner ring can be removed to fit larger terminals, outer ring diameter is approx. 44 mm/ 1.73 inch; Inner ring diameter is approx. 20 mm/ 0.79 inch; Diameter of inner ring after dismantling: approx. 30 mm/ 1.18 inch (Please allow slight dimension difference due to different manual measurement.) Fiber battery washers set: it can prevent corrosion around the battery terminals, prolong battery life, for use with 6 and 12-volt battery. Apply to: these battery terminal protector can use for both top post batteries or cables and side post batteries or cables.