The "Classic" is back. Roto Grip is proud to announce the release of the SD-73 "Classic". The ball that created the most controversy ever in the industry is back by popular demand. The Low RG (2.50) High Differential (.075) weight block is illegal by today's USBC standards, but since it was approved prior to the rule change it is perfectly legal for all USBC and PBA Regional competition. The Sure Grip solid reactive coverstock is a performance proven winner over the last several years and is still one of the highest friction coverstocks on the market today.