1pair (2Pieces) BMX Chain Tug/Adjusters-10mmColour -Black The main body of these is aluminium anodised black. The thread and nut appear to be chrome plated steel. The nut has a nylon bush (lock nut)to stop it coming loose.They are well made and look good.Thanks for looking. Have a look at my other Items while you are here. BMX Brake Blocks on Special.