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. These are 6 mm long so they work perfectly with any bolt on single chainring that does not have threaded standoffs.
Weight: 4 bolts - 10g
Material: 7075-T6 aluminum
Size: M8 x .75 x 5
Torque spec: 7-8NM torque w/ light grease on threads only