Impurities in A/C systems may include stop-a-leak additives, debris from compressors and seals, and built-up contaminants. Extreme Clean prevents contaminants from entering the A/C service equipment and plugging solenoids and other small ports or flow areas causing the machine to operate improperly, or in some cases, stop the operation completely. Use with any 134a service center. Simply attach the recovery hoses to the high and low side service hoses then connect to the vehicle. Use the hoses through the recovery and evacuation process. Remove the recovery hoses before recharging the vehicle. Visually inspect the filters and replace if contaminated. Kit includes high and low side hoses and 10 filters. Ship. wt. 2 lbs.