Size:Large (12.2" - 17.7") This large blood pressure cuff fits upper arms 12.2" to 17.7" (31 - 45cm) and is only compatible with the following A&D Medical and LifeSource brand blood pressure monitor models: UA-611, UA-651, UA-651BLE, UA-767F, UA-767FAC, and UA-1030T. The tapered fit is designed to snugly and comfortably fit around your arm. All A&D Medical blood pressure cuffs are durable and come with a 2 year warranty. NEED HELP? Our dedicated customer satisfaction team can be reached at (888)726-9966, and they can answer any questions or concerns you might have regarding your device. ABOUT A&D MEDICAL: A&D Medical and LifeSource by A&D Medical are doctor recommended brands of health monitoring devices designed to help patients and their families track and troubleshoot with their doctors, all from the comfort of their homes. The technology in the blood pressure monitors, activity monitors, scales, thermometers, and smart devices help make keeping track of your health easy.