1/4" x 3" x 4" Jumbo Black Shims. Color coded for convenience. Economical to use for all your shimming and leveling needs. For use in the installation of windows, doors, storefronts and insulating glass units. High-impact plastic jumbo horseshoe shims are weather-proof and will not rot, rust, stain or leach. Color:Black Thickness:1/4" Length:4" Width:3" Slot: 13/16".