My Viking 2460 has the combination shower and cassette toilet (aka “shoilet”) on the front and the sink on the back. Of course the drains are not together on the same side. And they are different sizes. The sink drain is a garden hose fitting and the shower drain is 1.5 inch PVC with a screw on cap to cover it. Not only that but dumping the gray water jug a couple of times a day is a pain and the big gray water totes are pricey. So the challenge was to figure out an inexpensive way To tie the two drains of different sizes on opposite sides of the pup together so that they could drain into a sewer hook up at the campground. Below is my solution. First, because the shower drain exits at an angle I needed a way to get a section of PVC to run under the pup and come out near the sink drain in the back. I found this at Lowe’s and it did the trick https://www.lowes.com/pd/Road-Home-1-1-4-in-dia-ABS-P-trap-Fitting/1002620080 I glued in a section of 1.5 inch PVC that ended just shy of the frame on the backside and glued on a female fitting so I could cap it off. This kept everything nicely tucked away when we’re on the road. Notice the plastic hanging strap. I put a bit of a slope so the water will drain properly and it gives a little flexibility/sway room to deflect any road objects that come its way. Then I made a screw in adapter that flairs out to accept a standard sewer hose. I bought the hose kit fittings and glued it in to a 3 inch piece of PVC. (Take the fitting with you when you buy the material to make sure it fits properly. The sewer hose fitting will be a little loose, but not sloppy and glues in fine). I screwed the adapter in place and marked the top to put in the plastic male garden hose end (cut the barb end down with a hacksaw) and cemented it in place. The finished adapter looks like this. Here’s what it looks like all put together and in use. I bought a dishwasher drain hose and cut it down to connect the sink drain to the system. It works like a champ and I like being able to use the shower and not have to drain the gray water jug anymore! Total cost @ $30.