Wolf Tooth Set of 5 Chainring Bolts + Nuts for 1X Color:Black This securely closes the shell Jackets This securely closes the shell using a stainless steel BOA® lace for the perfect fit and helps to effortlessly get you in and out of your boots at the beginning and end of the day Water resistant compartment inside roll top entry protects your gear and expands when you need more space These are 6 mm long so they work perfectly with any bolt on single chainring that does not have threaded standoffs These single chainring optimized bolts have a 4 mm hex socket on the bolt and a 6 mm hex socket on the nut so no spanner is needed