FREE GIVEAWAY - Join my facebook page [link]
and share this, and you might win it on the end of this month (March 2012).
Made out of 2 colored acrylics (perspex plastic) dual stacked, it's 6mm (0.2") thick and measures about 25x25mm (1x1in).
It is completed with an adjustable ring base, should fit most fingers easily, not for little kids though.
More photos and purchase info @ Etsy [link]
Use coupon code "DEVIANT" for a discount on checkout.