Description These air dryers are easy to install, require minimal maintenance and when service is needed you can replace the cartridge filter in less than 5 minutes. The dryer is to remove as much water as possible and deliver dry air to your patients. This pairs with a filter to clean the air, trapping any microorganisms present so they aren’t transferred into the patient’s mouth Hose Connection Inlet size hose: 3/8" Outlet size hose: 3/8" Special Instruction On the bottom of the dryer there is a releasing valve, you must release it for every two weeks. You will need to change the cartridge every 4-6 months.