FEATURES & FUNCTIONS : Adopt drum closed twin pump design. No noise, no bad smell, no spark, safety and long life. Digital timer adopts micro computer programming design and large display for easy reading and simple operation. The output pressure of pump can be instantly known from the pressure test push button. The new watch type pressure gauge which can clear show the reading replaces general water manometer. The vacuum bottle is made of PC, so it can be sterilized in high temperature and high pressure. But any chemicals such as antiseptic solution, cleaner, etc. can't be put in the bottle to avoid bottle breaking. But any chemicals such as antiseptic solution, cleaner, etc. can't be put in the bottle to avoid bottle breaking. Germ killing filter can prevent germs introducing from outside to secure safety. One large article box at the rear of instrument is used for storing the leading tube, catheter, etc. Stainless steel skeleton for easy maintenance, diagonal PU anti-static brake wheels for easy fixing. DF-500 is the slow/negative pressure suction unit and suitable for thoracic drainage