Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: Does it require much strength to screw it in?
Document: Seniors or people with limited strength or mobility can open jars much easier. You can hold jar with both hands and twist jar lid in the locking jaws. It has double faced tape to hold in place under the counter till you install the screws into the wood. Be sure to used the longer screws (2) in the thicker part of the unit and the smaller wood screw (1) in the thinner plastic  jaw area.
This item is easy to use and I purchased it for my 81 year old mother to use at her home. It does require that you screw the item to the bottom of a cabinet but the tape on the underside makes that an easy process. The teeth on the opener are VERY sharp.
With age comes the time when hand strength becomes a problem. Opening screw tops had become a real chore and pliers only handled so many tops. While searching Amazon.com I found the EZ Off Jar Opener and thought I might give it a try. This simple device works great. Even my skeptical wife had to agree.
This tool is relatively inexpensive, easy to mount and works great on all the jars and screw-cap bottles I've used it on. Seldom does a product exceed my expectations; but this one has. I've had it for a year of frequent use. I  also don't have any problems with my able hand or arm. I'm not sure how this would work for those with pain or limited ability to twist their wrists, as it takes some torque and strength to use.
This item makes opening jars very easy. I have found as I have gotten older that I do not have as much strength in my hands, that witharthritis  makes opening jars very difficult. This item completely solves that problem and it is inexpensive also.
My 88 year old father actually tried all the ones that people are familiar with, but ended throwing them all out. He was so pleased with the ease of this jar opener, that he  thanked me quite a few times, since he lost much of his strength in the last couple of years. Really a great product!
I saw some reviews dish this product because it didn't stay put. Pretty much complaining about needing screws.Well, it comes with the 3 screws needed (that I used for mounting the opener under a cabinet.) The opener comes with an adhesive pad that is clearly labeled as being an aid for mounting. That is, peel it and stick it where you want to mount it and it will be held in place making it quite easy to screw in the screws for a permanent mount.
My husband and i both have lost strength in our hands and wrists as we have aged. We are in a real bind with pickle jars, candles that get stuck with the lids on, fingernail polish...just about everthing that has any kind of seal. This was easy to mound and really works. I bought it for my husband for Christmas and so far i have used it several times and each time am amazed that something so economical could help our quality of life so much. I recommend this.
I bought this item a while back and I still love it as much as day one! It was so easy to use and it is totally inconspicuous. It works on every lid. I've opened big jars of pickles and tiny little vanilla bottles. I have rheumatoid arthritis and there are days when I have zero strength in my hands. This item always comes through. I highly recommend this item. Simple, easy to use, and it doesn't have any mechanics that can break over time.
Plan on peel, stick, and screw in. Then you'll be fine.
Answer: I think you are talking about the initial installation.  That would probably be like screwing anything into wood.  My mom needed someone else to do this for her.  It does have adhesive to hold it in position while you screw it in, but you want a good installation so you can use it with some force.  It's just a plastic disc with holes for wood screws to go into your cabinet underside.