About time! After having hamsters and guinea pigs over the last decade I cannot believe that I hadn't thought of this myself! We have 5 guinea pigs so I purchased 3 of the large lilac holders. What a game changer. It makes changing the water soooo much easier, there's no more fighting with those blasted wires! (I took great satisfaction in throwing them away). Our piggies find it easier to drink from, they're easy to install and adjust if necessary, and the water doesn't leak everywhere, just the odd drip now inside the cage on a lining blanket.
If you're thinking about getting one of these holders - don't - just buy them. Bloomin' brilliant.