• Size             Diameter           Perimeter
• 7                    17mm               53.4mm
• 8                   18mm               56mm
• 9                   19mm               59.1mm

Inner diameter: 17mm/18mm/19mm, width: 7mm

SHIPPING:
FREE Shipping for the US, Ca, AUS, Singapore, Japan, Korea, Malaysia, Thailand, Russia, Israel, Italy, Spain, Turkey, France, GER, UK, Netherlands, Norway, Sweden, Switzerland and so on.
Most countries in the world can send postal couriers. You can email us directly to ask if your area can be reached.
The European region usually arrives in 3-4 weeks. The Asian region usually lasts 2-3 weeks. The North American region usually lasts 2-3 weeks.
If you need to receive it as soon as possible, you can choose “UPS Express” option, usually within 5 days (excluding Saturday and Sunday). But you need to pay an extra $22 for shipping.