To use this Hypertherm 45A SYNC consumable kit, first, make sure your plasma cutting machine is turned off. Then, install the appropriate SYNC cartridge for your project, either the 428925 Mechanized Cutting Cartridge or the 428926 Fine Cutting Cartridge. When using, keep the machine in a well - ventilated area. After use, turn off the machine and remove the cartridges if you won't use them for a while. Store the cartridges in a dry place to prevent damage. Regularly check the cartridges for wear and tear, and replace them when they start to show signs of excessive use.