Cuff Basic Information: 1.The cuff has a 5mm diameter connector and a 6mm diameter connector. 2. The tube diameter is 5mm. 3.This cuff is only suitable for arm electronic blood pressure monitor. 4.This cuff has an inflatable tube HOW TO USE 1.Keep the lower edge of the cuff 0.8"-1.2"(2-3CM) 2.The air tube is on the inside of your arm and aligned with your middle finger. 3.The cuff should be placed on your arm at the same level as your heart. 4.Keep a certain space between the cuff and arm. Ensure that one finger can be inserted.