According to my experience this keychain tool is a must-have for anyone who owns a car... The wrench is the perfect size to fit in my hand, and it easily opens my valve covers without any issues. Plus, the keychain attachment makes it convenient to carry around with me wherever I go. The only downside I've found is that it's a bit difficult to use if you have large hands. But overall, it's a useful and practical addition to my automotive toolkit..