This is a dishwasher holder for 3 SodaStream caps. Unlike the bottles, caps are usually safe to put in the dishwasher. This tool restrains the caps in the position by screw that is partly uncovered allowing water to flow inside. I found this sufficient enough to clean it, however, I recommend to rinse the cup after cleaning with water to remove any detergent residue from the covered parts.
I designed this for my dishwasher, so I can't say for sure it's going to work for yours. There are two openings on each side, one of each is a bit wider. Unless rods in your dishwasher have very different thickness (mine is 4mm), you should be fine. Rod should sit in the opening very tightly to prevent strong water flow to move the holder. If it does, you don't even necessarily need to fix it on both sides.
You may also want to check out my other thing for SodaStream - a bottle dryer.