This auction is for one auto drinker as shown, great for birds and other small pets. They work on a low pressure gravity feed water supply and can be linked together for as many as one wants or blanked off as a sole unit. The bowl works like a ballcock in a cistern as they drink the bowl raises and allows more in. Bowl size is 60mm Dia 40mm deep Are really great no more dishes or drinkers to fill up every day and can go away for the day and know your animals are well feed and watered. Have a number of these to sell so if you are looking for more than 1 I can accommodate just email me once auction is won and confirm the number you require, depending on the number I may even be able to sharpen the price, shipping rate given below for multiple purchases