FATPET Nozzle Diameter 16mm Durable Small Pet Drinking Water Fountain Portable Pet Bottle Head Measure: 15.3cm x 6cm x 9.1cm / 6.0"x 2.4" x 4.3" nozzle diameter: 16mm You can easily snap the water Bottle on or off for cleaning and refilling water. Its top fits most standard water bottles and with screws, it can be fixed in any place , such as walls, wood, cages, etc Regular-sized nozzle is recommended for small-sized dog, medium-sized rabbit, cat. It's can install various sizes of bottles to accommodate specific size for your pet The water bottle comes with roller ball style nozzle, no springs, not only very easy and convenient for your pet to drink, but also will never hurt your pet when your dog is drinking