Best constructed jumper cables I've every seen in my 50 years of using jumpers. Clamps aren't too large, spring tension is reasonable, and the insulation on the clamps is well done, good bond of the copper to the clamp. The cables are a large diameter--expected at 1/0 gauge, but the copper isn't as flexible as good welding cable or good SC (entertainment cable) and I still wonder how flexible the jacket will be in cold weather. My advice; if you want the best cables. buy a length of SC 1/0ga cable, get clamps from Associated Equipment Co. and build your own.