Patented technology only from Drillmasters. Proven (over 25 years!) to improve marching scores and overall musician performance. Drillmasters ROLLED-HEEL™ guides the foot through the step. It acts like a golf swing training machine that lets you repeat the correct swing over and over until it is memorized and becomes habit. Golfers “groove their swing.” The ROLLED-HEEL™ “grooves” the students’ step.