Professional tool for commercial or occasional use -Manufactured from precision profiled stainless steel wire for strength and durability -When installed they provide strong permanent internal thread which resist heat and corrosion -Once fitted their position is maintained by the action of radial pressure between the coils and the flanks of the tapped hole -Replacement thread insert coil packs -Helicoil kit replacement threads -Size of the helicoil M5 x 0.8mm -This listing is for a pack of 25 -Comes in a little box compartment for easy storage and transportation