Heavy, sculpted edge stainless steel. The bangle is 20 mm wide and 10 mm thick. Screw lock (with flush head Allen screw, wrench included).
Other size, width, strength also possibly)..
S: 63/ 48 mm (to 18 cm)
M: 68/53 mm (to 19,5 cm)
L: 73/58 mm (to 21 cm)
XL: 78/64 mm (to 23 cm)