This effective and simple-to-install aluminum gutter guard recesses into the gutter and fastens to the front with stainless steel screws (provided). With thousands of holes, the rain water passes through the canals, making it E–Z for air flow to dry the debris and blow it away. FEATURES 4' Length pieces, Made for 5" K-style Gutter Systems Maximum Debris Load Fastens to the Front with Screws Heaviest Water Load Canals Allow E-Z Air Flow, Letting Debris Dry and Blow Away Solid Perforated Painted .019 Aluminum Does Not Disturb Shingles Includes zip screws to fasten the guards to the front lip of the gutter. (Zip screws included for one screw per foot) Like all gutter protection products, depending on your debris type and load, E-Z-Smooth Flow will require maintenance from time to time, by brushing off the top of the panels.