This durable nylon cuff is comfortable and easy to use and fits Medium arm sizes 9.4" to 14.2". The cuff has a strong Velcro hook & loop fastener that is tested for up to 30,000 uses and is backed by a lifetime warranty. Fits upper arm sizes 9.4" to 14.2". Comfortable and easy to use. Durable velcro fastener. For use with LifeSource or A and D Blood Pressure Monitors.