This is a black leather choker featuring a stainless steel plated D and O-ring attachment with spike studs. This black studded D and O-ring choker makes an alternative gift for gothic, punk, metal and other alternative fashion styles. The black O ring collar is suitable for fashion and play. The O ring comes in a variety of sizes from 1 to 2 inches. The model is wearing a 1.25" O ring, for reference. The O ring measurement is taken from the inside diameter, so the 1" O ring measures 1"/25mm from either side inside the O ring. The O ring thickness is 3-5mm either side so please add an extra 6-10mm to the inside measurement to get the full measurement and help decide which size is best suited to your needs.