The most important tool to a mechanical insulator is his or her knife. Every mechanical insulator carries at least one knife on the job and usually has a variety of fiberglass insulation knives for every type of project. The main considerations for selecting the correct knife is the length, the blade type, and the flexibility. Buy Insulation Products carries knives with blade lengths varying from 5" up to 10" long. We also carry serrated and non-serrated blades along with flexible and rigid knives. Buy Insulation Products carries the Dexter Russell insulator line of knives along with handheld knife sharpeners and sheaths.