Problem Solvers Chainring Steel Inner Bolt 12.5mm Set of 5

Stainless Steel, hex type.  12.5mm in length.

Inner bolts are used to attach a single chainring to the “granny gear” position of a triple crankset.  No nuts are needed.

You may need to use the granny gear spacers from your old crankset to get the correct spacing on the new granny gear.