Pro Bead Set 6 rolls a single oval shaped bead. The length of the bead made with this set is about 36mm and the diameter is about 20mm. This bead roller does have a bead piercing pin path through it, so the bead can be pierced through the roller, eliminating the likelihood of fingerprints, and possible distortion. Additionally there is a 1/16 inch rule on the edge of this to assist you with measuring clay according to directions, as well as s a line at the pin path to assist lining the bead up for piercing. A tube of bead piercing pins is provided with this bead roller. See our Pro Bead Rack in the Miscellaneous category. NOTE TO POLYMER CLAY USERS: Due to the size/diameter of this bead it is prone to cracking during curing. If this happens, plunging the bead into ice water directly from the oven does close the crack, leaving a tiny fracture line. This does not always happen. Your satisfaction is guaranteed with all of our products!