1. More water volume.RS04S - 4 gallons. RS04 - 7 gallons. RS04L - 10 gallons.

Each comes with a built in air reservoir, so you can fill it all the way up, and not have to leave any air space before you pump it.

2. High Pressure Spray. Road Shower 4S, 4 and 4L can be pressurized to 65 PSI.

Get 5-12 minutes of high pressure spray depending on pressure and nozzle setting.

3. RS04 compared with the RS02. The RS04S is the same size as the RS02.

The RS04 will have a more professional fill cap. It will thread by simply twisting the cap on and off. No more radiator cap.

4. Option to add another outlet on the opposite end. No matter if your vehicle is pointed uphill or downhill, you can drain the last drop.

There will be a side slot as well. Now you can mount your RS004 to the side of a roof top basket, or on any vertical surface.

5. Plug can be removed and an optional hose bib and shower head can be added.

This allows hands free showering with a water saver shower head.

6. Sporty new graphic.

While the Road Shower logo is printed on both ends of the tank.

It is designed to be pumped with a 12 volt tire compressor. A hand bike pump can be used in a pinch, but it takes a while, due to the high 65 PSI and the large size of the unit. A CO2 pump could be used as well.

It can also be filled and pressurized with just your garden hose by using the included female to female connector. No pumping required.

You can get longer run times by dialing the pressure back with the black handle on the elbow and/or the nozzle adjustment on the tip. Up to 10-15 minutes. The high pressure is good for cleaning gear. Dial the pressure back for showering.

If you fill it all the way up, and then pressurize it to 65 PSI, it is designed to run out of pressure about the same time as the water runs out.