Plastic knife- essential for top edge and window shaving- 5 Pack

These blades combined with the carbon steel blades will give you the cleanest top cut you can possibly get with not much skill needed. Better than a red dot or metal knife because the red dot will leave a small scratch in the film from the metal tip. These will not. 

These are actually high quality plastic knives not like the cheap ones you see at harbor freight. The blade stays nice and still in the handle. Great for beginner and expert installers