SK was a premium brand found in auto parts stores for years, but then they tried to compete with some of the other lower cost brands and kind of fell short on endurance in the last 20 years, but then so did everyone else, except maybe snap on, I have had SK, Mac, Williams, and a few other brands in my tool box, but I always stuck with Craftsman because of the availability and ease of returns when they broke, Snap On you had to chase down truck if they didn't make regular stops at your place.:roll: and the cost was high.