Product Description TA Zephyr is a chainring for road compact cranks. Specifications:Application:RoadAttachment:110 mm bolt circle diameter, 5-armTeeth:33 T, 34 T, 36 T, 38 T, 39 T, 40 T, 42 TGearing:2x9-speed, 3x9-speed, 2x10-speed, 3x10-speed, 2x11-speed, 3x11-speedTechnical Information:Material:aluminium (7075-T6)Compatibility:for Road Compact cranks (110 mm bolt circle diameter)also for MTB cranks before 1993 with 110 mm bolt circle diameter and hole spacing 65 mm (old Shimano MTB standard)Position: innerFeatures:hole spacing 65 mmblack or anodised silverdesigned and produced in France Note: The inner Zéphyr chainring (not middle, not outer) is also 11-speed compatible, provided it is combined with an outer 11-speed chainring. Chainrings with an older production date have an " 10" printed on them, while chainrings with a more recent production date have " 11" printed on them. However, there is no difference in compatibility (to 11-speed).The manufacturer recommends a difference between 12 and 16 teeth between the smallest and largest chainring.Manufacturer Numbers:black 33 tooth:PL-50110109-33silver 33 tooth:PL-50110102-33black 34 tooth:PL-50110109-34silver 34 tooth:PL-50110102-34black 36 tooth:PL-50110109-36silver 36 tooth:PL-50110102-36black 38 tooth:PL-50110109-38silver 38 tooth:PL-50110102-38black 39 tooth:PL-50110109-39silver 39 tooth:PL-50110102-39black 40 tooth:PL-50110109-40black 42 tooth:PL-50110109-42Contents:1 x TA Zéphyr chainring Manufacturer: Spécialités T.A. 41 bis rue de Laon 02150 Sissonne France france@specialites-ta.com