The Noisy Cricket is a compact two battery series hybrid mechanical mod. Before usage, you really ought to do your research or the Noisy Cricket could turn out to be a very costly and dangerous device. Hybrid mech mods need to be handled with knowledge and care, so please do your research before picking one up.
That said, for what it is, the Noisy Cricket is a pretty decent little device. It's super cheap, hits hard, holds up very well, is easy to take apart to service, and looks nice. My only complaint, really, is with the firing button. It's sort of janky and you have to hit it just in the right spot to get it to fire. The problem seems to be a common one as well and not limited to my unit only, unfortunately. It's not a deal breaker, especially for the price, but it should be noted.
As for the safety aspect of it, Fat Daddy Vapes makes an aftermarket kit that you can buy that replaces the hybrid cap with a floating pin that reduces the need for a protruding 510 pin on your atomizers, making the device considerably safer (but don't let that drop your guard--you're still using a mech mod).