From the campaign:
What is a Spinner Ring?
A spinner ring is designed in a way that an outer smaller ring spins in a grooved inner ring that slips onto your finger.
Features of Dice Rings
Portable - You can take dice rings anywhere. No worries about rolling them into a heater duct or losing them to a hungry pet. They will stay firmly attached to your hand. Unless you’re a zombie… then no guarantees.
Made from stainless steel - Our rings are made from the highest quality 316L stainless steel, a very strong and durable alloy that resists scratches, dents, and unorthodox abuse (troll punching). Like most other jewelry (even gold), it is an alloy. This type of steel contains 10-14% Nickel. For anyone who does not have a sensitivity to Nickel, these rings will be perfect for you. Unfortunately, we just could not get a hold of any adamantium or vibranium.
Produces fair rolls - The numbers are well distributed across the outer spinning band. There are no concentrations of high/low numbers, so they cannot be purposely aimed for or avoided. No cheese rolls.
Occupies idle hands - It is an awesome accessory to occupy idle hands and calm your mind. Spinner rings (also called worry rings) are frequently used as a stress relief tool, and are beloved by people with ADD everywhere.
Stylish - With these you are looking nerd chic!