I bought these to make my own quick disconnect cables since they were a thicker gauge for a very good price. I got to say I'm very impressed with the quality of the wire for being so affordable. The clamps are awesome and have a side that allows you to clamp onto battery terminals or bolts perfectly. They open wide too. Just note it is copper clad aluminum which is stated already. That should be just fine for my purposes and for just about every purpose of jump starting a car, especially 4 gauge wire. Overall I'm very impressed and would definitely buy these again if I needed a decent set.