The ring is 6mm wide (about 1/4"). It is made of aluminum and it's adjustable in size. I have them in two sizes, the S-M will fit sizes 6-9, the L-XL 9-13.

Delivery times are about:

For Europe: 4-14 working days

For USA: 3-7 working days

For Canada: 3-7 working days

For Australia, Singapore & New Zealand: 12-20 working days