Hello Buzze1; Since the circumference of the cuff has been clarified, the only thing missing is the width (height). This is 13 cm. For me as an adult, everything fits wonderfully. But if a child's upper arm is not 13 cm long, the product is probably too big. So: Suitable for adults, for children depending on the length of the upper arm. Possibly too small for adult bodybuilders. Happy Easter

Hi Buzze1...
Mr Diebold should probably have written the word (children's sizes) with "inverted commas".
Anyway, the cuff has a circumference of 22-42 cm and is therefore definitely for adults.
Why don't you measure your biceps? If they are over 42 cm in circumference, you will have to choose a larger cuff or a different device.