Material: Brass/Copper and in few brass and copper both.
Size: Inner diameter is approx 7.5 to 8.5mm and outer diameter is approx 14 to15 mm(as you can adjust the size as by 1mm)
NOTE : Since these piece are handmade there may be slight discrepancies in the shape/ size and can not be considered as defects. If you have any questions, comments, concerns please let us know before you purchase so we can make sure your shopping experience is as smooth as can be.