The waist size range for the Apollo Essentials Adult Diaper Pant Unisex is based on your waist or hip measurement, whichever is larger. The Medium size is suitable for a waist or hip measurement of 90 to 110 cm (35 to 43 inches), while the Large size fits a waist or hip measurement of 100 to 135 cm (39 to 53 inches). To choose the correct size, measure both your waist and hips and use the larger measurement. Selecting the right size helps provide a comfortable fit, better leakage protection, and improved ease of movement.