Wolf Tooth 1x Chainring Bolt Set - 6mm Dual Hex Fittings Set/4 Ultraviolet PurpleAluminum bolts for single ring chainring setup on common 4 arm cranks 6mm long, the bolt length is laser engraved on the head 4mm hex on the bolt and 6mm on the nut, torque to 6 7 Nm maximum, use light grease Made in the USA from 7075 T6 aluminum alloy TECH SPECS Model Single Chainring Bolt Set Kit Single, 4pc Size 6mm Material Aluminum Color Purple