M12; internal diameter 13mm; external diameter 24mm; thickness 3mm
M14; internal diameter 15mm; external diameter 28mm; thickness 3mm
M16; internal diameter 17mm; external diameter 30mm; thickness 4mm
M18; internal diameter 19mm; external diameter 34mm; thickness 4mm
M20; internal diameter 21mm; external diameter 39mm; thickness 4mm
M24; internal diameter 25mm; external diameter 44mm; thickness 4mm