Instruct: Classify Amazon reviews into positive or negative sentiment
Query: calipers are challenging

I knew that learning how to use calipers was going to be challenging, but I did my research and had a friend help me. Others had recommended this device. First problem is that the battery door (uses a watch battery) kept falling off during use. Okay, so I tape it back on to keep the battery in place. Taking caliper measurements yourself as a novice is just really hard to do. I tried explaining to my husband how to do it, and even still, wildly different readings each time.To me, its not worth the hassle and confusion. So far, I'm pretty happy using the Omron.