SINZ 4 bolt chain ring are the finest affordable chain rings available. Super lightweight and machined for a perfect fit. Manufactured to fit the 4 bolt 104mm bolt pettern found on many BMX cranks. Laser etched logos and size markings make the SINZ chain rings stand out. Fits 3/32 or 1/8" chains. Available in 36T through 46T in black. 75g each.