This is the PVC 1/4"mpt x 1/4"comp angle pitcock valve used with the larger fountain plumbings where a 3/4" threaded tee, bushing, and this valve was used to achieve the constant flow feature. Instead of using a side tapped float valve like the 11142, the factory installs a tee and bushing behind a regular float valve for this pitcock valve to screw into. Then, basically, you'll adjust this angle valve to trickle water into the unit (even if the float valve is shut off) and cause the waterer to overflow itself with fresh, warmer water to keep the temperature of the water in the fountain above 32 degrees. This constant flow feature can be used on most any fountain that can use the 3/4" male valve with side tap like the 11142, or plumbings with this angle valve installed, but the units that have a built-in overflow provision and a pipe can be installed to run the water away from the area is the most likely candidates. Otherwise, you have a muddy / icy mess around the fountain.