1) Wide range brass knurled nut embedded insertion tip head include M2,M2.5,M3,M4,M5,M6,M8 to meet your most installation needs 2) Screw installation design easy to change different heat model, no need to take off the whole tip,just screw off the tip head and put on a one 3) Tip head made from brass with high strength and good heat conduction ensure better heat insertion performance to get a smooth and clean insert. 4) Ideal for install heat set insert to your 3D printing parts enable you assemble and disassemble your projects easily, but won't ruin or contaminate your part rather than a normal soldering iron tip that either stuck or penatrate the insert hole this heat-set insert tool kit is designed to turn your ts100/ts101/pine64/936 soldering iron into a portable heat insert pressing tool to expand their functions. Colour:Gold & Silver Material:brass Package Contents: 1 * Heat Set Insert Tool Set