NOCO NCP2 MC303 Oil-Based Battery Terminal Protectors (Pack of 2)

When changing car batteries - - either by yourself or via a mechanic - - it's a good idea to add terminal protectors to prevent battery gases from corroding the battery terminals. These fit the bill nicely. They are made of felt and a wax-like substance, such as paraffin or similar. Before connecting the new battery, put one of the two rings on each terminal. Easy-peasy, and avoids messier alternatives such as grease and inhibitor sprays, which can degrade over time, not to mention that improperly secured terminals could slip off with mis- or overly-applied grease and similar products. A minor quibble: I wish the rings came in two colors to help quickly identify the terminals polarity (i.e., positive or negative). However, the all-black colors do not affect the functionality, and most car-savvy people would check the battery, itself, for the polarity, when the need arose. As a backyard mechanic of 40 years, I have never had corrosion issues with this and similar felt rings, so I strongly recommend this product.