When I saw the split anemometer for under $40 I ordered. This has pros and cons and 4* is generous - I'd give 3.5 if I could. I despise devices that REQUIRE A SCREWDRIVER to change the batteries - especially when product shipped with 4 cheap AAA batteries. While they give you a nice carry case with custom insert, and a USB cable, there is no tiny philips screwdriver included. In a portable device that you may carry around and have an issue with battery - and now to do anythingm, you need a very small philips screwdriver. My second issue is the button interface. I do not find it intuitive or easy or friendly at all. Third problem - the printed owner manual included had early error that reduced my confidence - the table describing the oddly named buttons like Tauto or M had #s mix-up making already confusing interface more so. (The online version linked from product page does not have the error.) What I liked about this was the 2-piece and the air flow and air temperature features along with velocity. I'm not sure how accurate this is, but I haven't seen anything that is better than this one in the price range - at least for now, but there is definitely room for improvements.