Custom made...very heavy bike chain that are available in three sizes (see options) and are 3/4 inches wide and heavy duty clasp. This is a colored stainless steel chain bracelet that really grabs attention. These are not cheaply made...we wanted quality when we had these made and that's exactly what they are. NOTE: Please measure your wrist size prior to ordering. As an example, I (Bill) have an 8 inch wrist and the 8 1/4 inch bracelet fits great!