Whisper attaches to 99% toilets right out of the box in about 10 minutes.
To be 100% certain confirm the following:
1. You'll need to be able to take your toilet seat off.
2. You'll need to be able to access to the water inlet on your toilet tank for attaching the water splitting 3-way adapter. This provides freshwater to Whisper from the water supply on the wall – the same water you brush your teeth with.
* If you have a stiff water pipe you will need a flexible water supply hose.
* If you don't have access to the water inlet on your toilet you'll need this T-adapter.
This T-adapter linked above connects to the water supply valve on the wall instead of the water inlet on your toilet. Standard water supply valves use a 3/8" fitting. To be 100% sure of compatibility, check with your local hardware store.
3. You'll have to place whisper on top of the bowl and have a few inches to the right of the bowl for the control box. Toilets with french curves are not compatible: