BLACK ARMOUR REPLACEMENT BLADES FOR GRAF ULTRA/COBRA HOLDER. Bladetech Hockey focuses on two attributes: innovation and quality. They are the first company to introduce âflexibleâ hockey blades that help increase performance with added health benefits. This patented technology is known as "Flex-Force". Thanks to the unique blade design, the front portion of the Bladetech replacement skate blades flex up into the holder of your skates, stores the vertical energy, and then releases it when you extend your stride. This innovation will increase your acceleration and help you skate up to an average of 5% faster! Not only do the Bladetech replacement skate blades increase your speed and acceleration, but they also help reduce lower body injuries. Thanks to the flex of the blade into the holder, it absorbs the large-impact forces while skating and reduces pressure on your ankles, knees, and hip joints. This will help you to be more efficient on the ice and allow you to play longer! Bladetech replacement skate blades are made with the highest quality steel available, extending the length of time between sharpening by almost double. *All returns are at buyer's own cost. Details will be shared when a return is requested.