This raises the waterer by 1.25 inches so the chicks splash less and the bedding doesn't get as wet.

This fit the water base that I received when I ordered the Little Giant Waterer base from Tractor Supply Company: https://www.tractorsupply.com/tsc/product/little-giant-1-quart-screw-on-poultry-waterer-base-2167117 The actual base I received looked a little different than what was pictured on their site so your mileage may vary.