Prime-Line Products U 9807 Sliding Window Lock, 1/4 in., Extruded Aluminum, White, Double Thumbscrew Used on vertical and horizontal sliding windows as a secondary window lock For use on 1/4 in. max. thick fins White painted finish Extruded aluminum construction with double thumbscrews (steel) Used on vertical and horizontal sliding windows as a secondary window lock For use on 1/4 in. max. thick fins White painted finish Extruded aluminum construction with double thumbscrews (steel)