Ariane Stiegler and Quietude The Amateur Rider Association of America (ARAA) has committed to standardize the height and the width in the Low, Medium and High Amateur Owner Jumper divisions across the country. With the USEF new rule and sub-categories of 1.20m/125m, 1.30m/1.35m and 1.40m/1.45m this year, it is now easier for shows across the