Sk (SAE) 6 pieces. The X-Frame® Fractional Combination Wrench Set in chrome by SK Tools delivers the best wrenches for maximum power and precision in tight spaces. The SK X-Frame Ratcheting Wrench features the latest technology to make jobs faster and easier. The ratchet system is comprised of six pawls that operate in a clocking mechanism to ensure that two of the pawls are fully engaged with the ratchet teeth at all times. The small 1.7 degree arc swing enables work in tight spaces that are unavailable to other wrenches. The SK X-Frame design spreads the workload evenly across the wrench body in the same way that an I-beam spreads a load for a bridge or building. Unprecedented strength that exceeds ANSI specifications by 5 times. The SK X-Frame shape allows for increased breaking power and extends the life of the tool.