I use a set of clear and a set of blue and change back and forth, helps me to keep track of where I'm at and be sure everyone gets fresh water! Now we have green for medicine water:)
These tubes work great for the smaller birds like finches and canaries
Top Rack Dishwasher safe
Only good for short periods, not much water 20cc, tiny tube
Dino Drinker - 20 cc - 1/2 oz Plastic bird waterer from Italy - 7/8 " diameter x 3" high with spout on. Easy on and off and holds about 1/2 ounce. Available in Clear, green or blue. These work great on hospital cages, show cages and travel cages. Tiniest water tube I have ever seen:)