Product details:

The clean, smooth design elements integrated into the Kelston ensemble allow the versatile products to fit seamlessly into many existing dcors. 2-1/8 In. trapway. Combine with the K-4474 Kelston toilet tank to create K-3754 Kelston Comfort Height elongated toilet, or combine with the K-4469 Kelston 1.28 toilet tank to create K-3755 Kelston Comfort Height 1.28 elongated toilet. Please see K-3754 or K-3755 Comfort Height toilets for full details. Combines with the K-4474 or K-4469 tank to create a complete K-3754 or K-3755 Kelston toilet. Coordinates with other products in the Kelston collection. Standard 12-inch rough-in.