ThermaKnife™ Tray Trimming Knife. Trim and scallop bleaching trays, nite-guardsThermaKnife is an improved way to quickly and easily trim bleaching trays, mouthguards and many other thermoplastic materials. The adjustable temperature control makes it easy to customize the hot tipped blade for your cutting speed and material thickness needs. Features and Benefits: Ultra fast heating circuit gets tip to ideal temperature in seconds and saves time Lightweight pen with sharp, permanent tip promotes improved comfort and control Fast