Muteki 31886U Chrome Blue 12mm x 1.5mm Open End Lightweight Spline Drive Lug Nut Set with Key, (Set of 20) 21 millimeter length and 20 millimeter outer diameter with open ended spline drive design Open ended Muteki lug nuts weigh a mere 25 grams each 21mm length 20mm outer diameter with open ended spline drive design Open ended Muteki lug nuts weigh a mere 25 grams each