Not shown on any of the web's photos --- there is a sizable cut-out/hole on the back of the tank, near the lid. Probably to make install easier ... but, eewl...just thinking what can fall into the tank over time. Plus the like was damaged. Not easy to return this item, but it's going back to Wayfair.

Nice looking toilet for a tight space. Works well and fits perfectly. Good for the price too!

I wasn't planning on purchasing this as the Durastyle toilet bowl was misleading and did not indicate that the tank was not included.