Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: Will the teeth dig into a smooth plastic cap?
Document: $15 seemed like a steep price to me, but with all of the 5-star reviews, I bit.It's fantastic. Sure, it's a disc of plastic with what appear to be saw teeth on one side to grip/dig into the cap of the item you are trying to open, but it works- every single time. I bought one for myself and one for my mom- a long time sufferer of arthritis.
This works exceptionally well. Be forewarned though, that if the cap is plastic (as in nail polish), the sharp teeth will cut into it. I'd rather that than not being able to open it though. I'd definitely recommend this to anyone with arthritis or, for large containers, just small hands.
Saw teeth really grab to loosen cap easily. First try hot water on cap, tapping cap lightly on edge, and puncture lid (unless re-using). Will not tighten cap in reverse motion. Mounted mine vertically to apply side body pressure to jar while turning, as my other hand too weak to hold it alone. Basically a one hand operation anyway. Must be screw mounted--do not over-tighten as will crack plastic.
Works great but watch those teeth. If you don't turn too abruptly, the teeth don't dig in so much and leave marks. Otherwise, opens everything I've put to it.
Has worked on every cap I've tried to remove but be aware that it can leave sharp burrs from the teeth.
When I brought this, I was a little worried that this will not work because I read some of the reviews that said the teeth edges will damage the bottle cap. I installed it underneath my kitchen cabinet with the tip of the "V" pointing toward me. (unlike the photo) This way I can use my hand strength better. The first time I used it to open a medicine bottle, the teeth did created a scratch mark and it did't open the cap.
We had a metal version of this in our kitchen when I was a kid. This thing is plastic with metal teeth, but it seems to do the job just fine. I have problems with my thumbs, so opening even easy jars is impossible for me without this gadget.
My mom loves it. Now she can open any sized jar - even when no one is around to help.She excitedly reports that it even works on tops to very small jars.The teeth are metal, so if you use it on plastic tops, it may chew up the top a bit.
I usually don't have problems opening jars but some really are a challenge because of the jar shape or a smooth lid. A recent jar of relish proved impossible for me and anyone else who tried so I choose the EZ Off from the many different choices, primarily because I didn't want yet another kitchen gadget clogging the drawers.The unit seems well-enough made, a fairly tough plastic and a very simple concept. A major advantage is that you can grip the jar with two hands while using.
Needed a good jar opener for my elderly mother. Looked at the plier type but they were too large for her hands to grip due to the osteoarthritis. Picked up this item due to the good reviews. Installed with just 3 screws to the bottom of the cabinet. It was thoughtfully supplied with some sticky tape to aid in initial positioning. In all, took less than a minute to install.The sharp teeth on the unit grip plastic and metal lids with ease.
Answer: yes, it digs in and will open anything, I love it