This is a good general purpose sensor for field use. However, the description is misleading as it refers to a "lock finger button". While it's more like a "fingerwheel" that lets it twist and turn to lock. There is a manufacturer that makes the same sensor with a grip - which I think is more convenient and faster. Also be careful - no case or case is included! I think that's a disadvantage. How does the manufacturer expect you to wear it? The device isn't exactly cheap - and for such a price, it should come with a carrying case!