This cuff is suitable for use on upper arms with a circumference of 22 - 32 cm. Compatible with the following OMRON devices: M2 Basic (HEM-7121J-E), M2 (HEM-7121-E), M300 (HEM-7121-D), M1 Basic (HEM-7121J-AF / HEM-7121J-LAF), X2 Basic (HEM-7121J-EO).