Dead Ends Drain Tube Is A Dental Waterline Cleaning Accessory That Is Performed At The Beginning Of Mint-a-kleen?s 1st Step: Air Purging The Dental Waterlines. the Drain Tube Is A Clear Tube With A Male Quick-connect On One End And An Open Tube On The Other End Designed To Open ?dead-ends? Such As The Dental Unit Water Quick-connect Outlet (for The Cavitron). dental Units With Water Quick-connect Outlets Are Called, Dead-ends. A Dead-end Is A Blocked Water Passage Within The Dental Unit. Water Does Not Continuously Flow And Is Stopped By The Quick-connect Outlet, Resulting In A Reservoir For Bacteria. the Drain Tube Provides A Quick And Easy Answer For Opening Dead-ends. Instructions: if You Have A Water Quick-connect Outlet On The Dental Unit, Place The Open End Of The Drain Tube In The Saliva Ejector. attach The Male Quick-connect To The Female Water Connect Outlet On The Dental Unit. turn Saliva Ejector On. turn Dental Unit On And Pressurize Dental Water Bottle. remove The Drain Tube After Dental Water Bottle Is Empty. this Is The Beginning Step Of Air Purging The Dental Unit. continue Completing Mint-a-kleen?s 1 Step: Air Purging The Waterlines: Handpieces And 3-way Syringes. benefits Allows Complete Cleaning And Control Of Microbial Contamination In The ?dead-ends? Of The Dental Unit. allows Air Purge Function For The Water Bottle On The Waterlinex. Enhances Dental Unit And Waterline Cleaning Process By Eliminating Water From The Water Bottle (on Systems That Do Not Have Air Purge) So The User Can Air Purge Easier.clear Tube-designed To Open Water Quick-connect Outlet On Closed-system Dental Units For Optimal Microbial Cleaning. designed To Allow Air Purge Function (emptying Of Water Bottle) On Water Bottle Systems That Do Not Have That Functionality (dental Unit Must Have A Water Quick-disconnect Outlet.)