Warm Prompt: After connecting to the power source, please press and hold the pink button for three seconds to start.Heat Insert Nut Iron Tip M2 M3 M4 M5 M6 M8 Brass Thread Embedded Kit Heat Insertion Tool for Plastic three-D Printer Soldering IronName: Brass scorching soften insert nut screw and Soldering IronMaterials:Nuts:BrassScrews:304 Stainless SteelNuts size:inner diameter*length*outer diameterScrews size:thread diameter*thread length(not consist of the screw head)