Absolute BLACK Premium Oval chainrings for FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K, K-Force. This model fits all 4 and 5 bolt design cranks. 4&5 bolt cranks are identical except the one hidden bolt behind the crank arm in 5 bolt design which is not needed. These are finest FSA compatible chainrings on the market in terms of shifting, stiffness, smoothness of pedaling and manufacturing quality. 10/11/12spd compatible. Di2 Compatible. ABSOLUTE BLACK Road Oval 2X Fsa Abs Chainring Black Features  Compatibility: All FSA ABS (asymmetric bolt spacing) cranks like Gossamer, SL-K, K-Force, K-Force Light. Both 4 and 5 bolt versions.One model fits them all. Di2 Compatible. 10 / 11 / 12spd compatible. ABS cranks only. Material: cnc machined 7075 Txxx Aluminum. Long-lasting construction. Type II anodizing Size (Weight) 34T (32g) 36T (33g) 38T (38g) 39T (41g) 50T (115g) 52T (132g) 53T (134g)