Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: how big of a hole do you need in the counter top for this item?
Document: I've been using this dispenser for the past 3 years and have had no issues with it. No discoloration or leaking or corroding (at least anywhere visible).Really easy to refill! I just pull the pump mechanism up and out then begin pouring in the dish soap from the top. No need to crink your neck and shoulders trying to unscrew the bottle from under the sink.
As others have said elsewhere, the instructions do not match the actual product, there is only one plastic mount washer that is used to adjust the height of the white threaded mounting tube from under the counter, the bottle and thread tube is held in place by screwing on from the top the stainless top piece. Make sure the threaded mount tube is flush with top of counter and it will mount perfectly.
This is a perfect addition to the three hole Danze Amalfi kitchen faucet if you have 4 holes. High quality product.
Takes quite a few pumps to get any soap out of the dispenser - then it continues to leak soap into the sink. When you need soap again, quite a few pumps - then the leaking.... Pain the arse!!!! !
I love this dispenser. It is stainless steel and stays clean and does not water spot. It's a little difficult to fill, but I would still recommend purchasing this item.
I do not like this item. It does not dispense soap as I though ti would.It has to be pumped to many times to get enough soap out to do anygood. I would not recommend this anyone. Also it is very cheaply make.
its a nice sleek design, but leaks soap almost every time! and its really frustrating to clean. with that said its not the worst, you definitely cannot fill it to the tops. it only leaks on the counter, thankfully not anywhere else.
Pros:- Looks good.- Feels solid. The parts you touch are metal, which is not a given in this category.- Has a nice long arm, so it will very likely clear your counter.Cons:- It leaks soap. Not all the time, but enough to be annoying.
The finish is a good stainless steel and matches perfectly with our stainless sink and faucet. The nozzle is long enough to clear the sink/counter. Soap reservoir is quite large and holds plenty of soap. Very pleased, would purchase again.
With my old Kohler dispenser, I was able to pump the dispenser with the same hand that is holding the sponge. This is a big deal when washing a sink full of dishes. For some reason, the Danze pump is not very smooth requiring the strength of  second hand to depress the bump down. I purchased their matching Faucet to go with this dispenser and am pleased with the faucet.
Answer: Mark, I just looked, but I really can't tell because I had to look under the sink and the area where the hole is just happens to be blocked. The inside part that goes through the hole is a little over an inch. However, there's an outside plate surrounding the dispenset that sits on top of the sink. Why don't you call the company and they can tell you the size of the hole. Sorry, I wish I could have been more of a help. Listen, before you buy this item, I just want to give you a "heads up." I have had mine for about three years. It works well, but the finish is beginning to wear on the top part that you press to dispense the soap. I also have the matching modern faucet that looks like a big candy cane. Although I purchased it from Amazon too at a great price, my husband and I noticed that the underneath finish is peeling. Also, the faucet broke away from the piece it sits in and now our faucet looks limp. The faucet retailed for over $600.00, but it is not lasting. I paid less than half for it on Amazon. I should really complain to the manufacturer, as a faucet this expensive should have worn a lot better. I hope I have given you some insight on this product before you buy it. Both my faucet and dispenser look great, but I am not happy with how they are both wearing.