"Sink Again" is made to fit tanks measuring 17" - 20" (measured with the lid off). With patent pending fill cycle diversion, you will see an immediate difference in your bill. This is a great fit for most 1.28 GPF and 1.6 GPF toilet tanks. For smaller than 17" tanks (measured with lid off) please use our original version. For large rectangle tanks of at least 18" x 8," (measured with lid off) please purchase "Sink Bigger". For larger than 19.5" tanks (measured with lid off), please purchase our original together with the expander sets sold separately. For improved fit, we recommend purchasing We have recently discovered that this "sticky tack" product is an excellent complimentary product for some SinkTwice customers who are seeking to affix the sinks tighter. "Loctite Fun-Tak Mounting Putty Tabs" with this purchase as that can help affix Sink Again to the target toilet tank.  Please note:  The toilet and toilet paper are not included - the product being sold is the sink and faucet combination only