This is a replacement push sole designed for the KR Strikeforce and Hammer Bowling Performance Bowling Shoes.These are designed for the heel of either foot for right or left handed bowlers. No Trimming Necessary as these come in sizes made for your shoes. Simply select the correct size in the drop down menu. Petite: Womens Sizes 6.5-7 Small: Womens Sizes 7.5-9 andMens Sizes 7-7.5 Medium- Womens Sizes 9.5-11 and Mens Sizes 8-9.5 Large: Mens Sizes 10-11.5 X-Large: Mens Sizes 12-13