PERFECT SOLUTION: Attach ice dam heating cable to your roof without using penetrating fasteners (nails, screws, etc.), which WILL cause roof damage. EASY INSTALLATION: Once you install heat cable with Grip Clips you will never go back to nail-on clips! Simply push the clip onto roofing, hook your heating cable onto the clip, and pinch to secure. Nail holes avoided! NO TOOLS REQUIRED: No tools needed and can be installed in cold weather. UNIVERSAL: Compatible with all manufacturers of ice dam prevention heat cables and most asphalt shingle roofing systems. Select the correct Grip Clip size for your roof material. Model 325 for 1/8" to 3/8", Model 625 for 3/8” to 5/8”, Model 875 for 5/8” to 7/8”. MADE TO LAST: Grip Clips will not loosen and can hold over 40 pounds per clip for a secure long lasting solution. Once you install heat cable with Grip Clips you will NEVER return to nail-on clips. Grip Clips WILL NOT void your roofing warranty (unlike traditional nail-on clips). NO TOOLS are needed and Grip Clips install 10x faster than nail-on clips. Because only ONE clip is used on the bottom of each serpentine heat cable pattern, Grip Clip installations require 30% less clips than traditional nail-on roof clips. Grip Clips can be used on a wide variety of roofing materials which range in thickness from 1/8” (Model 325) to 3/4” (Model 875), including cedar shakes, Davinci shakes/slate and all other types of synthetic roofing. Grip Clips are the ONLY heat cable clip that allows for a building-code-compliant application of heat cables near the center of the roof valley, where you want them.