Assuming the RV is level and the water pump is off and has been either cleaned out of water, or RV antifreeze has been added already. Simply screw this blow-out into the outside "community water port" (the port has an internal pressure valve that should be relieved of its pressure by opening a faucet and pushing on the plastic valve behind the hose seal screen (like on the female end of a hose) and attach a compressor (max 25 lbs pressure) AFTER opening a sink faucet first.Turn on compressor AFTER opening a cold sink faucet, then open the hot side, close cold side, go to second sink, open cold, close hot on first sink, on second sink open hot and close cold (do all sinks blowing out water from each hot and cold line, not developing pressure - always keep a side open) turn on the inside shower cold side, turn off sink hot side, back to shower open hot, close cold, flush toilet and keep open until water is out and mainly air comes out, same if you have a wand then close them, leave shower on/open and go to the outside shower and open cold, go back to inside shower and close hot, then go back outside and turn hot on then  cold off. The key is to keep air pressure flowing through one faucet all the time and to air-out each and every faucet or place where water may freeze, and not develope pressure in the lines that could blow a seal and cause a future leak. Turn off the compressor and be sure all faucets are closed. Add RV antifreeze to all P-traps and some into gray and black water tanks. Maybe a total of 4 gallons will be used, so have 5 handy.You can Google-search for free RV-winterizing instructions on the internet, buy a thorough RV winterizing book or e-book on Amazon, or check with your RV dealer. The internet and book has info on other things to winterize (batteries,hinges, etc., the RV place may have classes, and simplified devices such as a pump bypass kit, and RV Antifreeze, or check with K-Mart, Home Depot, Shopko, Target, Sears, Hardware stores, etc. Most any store, including Amazon, has RV Antifreeze in the fall which IS different from car antifreeze, ans a great selection of RV Parts; look for -50 degree formula, pink RV antifreeze.This air-hose blow-out and the tire-stem type work the same, I have one of each, just depends on the compressor line-end you use. Both types are highly recommend and I recommend Amazon ans Prime.  DO NOT ADD RV ANTIFREEZE TO THE HEATER OR EMPTY FRESH WATER TANK (waste of liquid, money, time, and it's hard to dilute and flush out in the spring); just be sure they are drained as best you can, and closed. Best to buy a pump diverter kit as it makes the process simple and saves you a lot of antifreeze. Antifreeze should be in all P-traps, shower drain, and some in both septic tanks; let a little antifreeze drain through the septic gate-valves to protect them from pockets of water. Hope this helps. What you miss can mess up RV time next year.