What are the product dimensions?

Lifetune One - is 19.8mm (0.78in) in diameter.

Lifetune Flex - is 35mm (1.37in) x 35mm (1.37in).

Lifetune Go - is 30mm (1.18in) x 30mm (1.18in).

Lifetune Zone - is 53mm (2.09in) x 53mm (2.09in).

Lifetune Zone Max - is 122mm (4.80in) x 65mm (2.56in).