Kitchen Drawer Slider Guide

This looks like a type of drawer spacers. These go on either side of a track to make sure it's stable and held firmly in place. 

Yours is a little more complicated than the types we carry, but you may still be able to use one of ours as a replacement. The four sizes we carry are the 32-352B, 32-339, 32-334, and finally the 32-350. Look these spacers over and see if any would fit in your drawer.