One for my colleague and me

This device I ordered twice, for me and for my colleague.
I am thrilled with the ease of use and reliability. The batteries (2x AAA) last forever. For almost two years now I have my device already in use. Well, I do not think every day a lecture. There are more 5-8 per year. But always when you need him, you take him, checked by switching on whether the indicator light turns green and off you go. With around 40 euros it costs a bit, but this one has something good. Another practical feature is the pocket. I do not know how to improve this product.