Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very useful

this product is really useful. I tried opening an olive jar, but my advice will be is to put one of the flat gribs underneath the jar and use the other one to open the jar, as mine slipped while i was trying to open it. it also has a very strong rubbery/hospital-like smell so you may want to store it in an open place. very good product