We have listed the B-Labs elliptical chainring with alternate narrow then wide teeth from Bionicon. Available in 38 or 42 tooth versions it will fit any 110bcd crank. With the increasing popularity of a single ring drivetrain in cyclocross, riders looking to go 1x for 2015-16 can use this chain ring and reduce the weight of their bike significantly, help reduce issues with mud clogging the drivetrain and a cleaner look. Works with any 11 speed system. 61g for the 38T version or 82g for the 42T version. I will be fitting one to my bike so lookout for some comments from me later in the year.