Funn Solo DX Narrow Wide Chainring for 9 10 11 12 Speed Chain, Fits SRAM Direct Mount Interface Crankset, 6mm Offset, Single Speed Bike Chain Ring for MTB, BMX Bike and Road Bike (28T, Black) : Sports & Outdoors - Amazon.com
absoluteBLACK Oval Narrow-Wide Direct Mount Chainring - 30t, SRAM 3-Bo
SRAM to license narrow/wide chainring design - BikeRadar
Amazon.com : Funn Solo DX Narrow Wide Chainring for 9 10 11 12 Speed Chain, Fits SRAM Direct Mount Interface Crankset, 6mm Offset, Single Speed Bike Chain Ring for MTB, BMX Bike