At under 2 kg with enough air for 6-8 minutes to a recommended depth of 3 metres and rechargeable with a hand pump or car compressor this device is rather cute: https://www.minidive.com/minidive-pro/
Evidently it is not safe, so you should not buy it. Here is a comment from a qualified diving expert: Joanne.
|Hi, I am enjoying your blog, however, my other hobby is diving , both scuba and free, and have been diving for 15 yrs plus. I am commenting to beg you to remove this post. The above item is a death trap, especially for inexperienced divers for a number of reasons. Unfortunately, it is also appealing to inexperienced divers without proper training. All Australian dive stores refuse to stock this product, however, links to an overseas store like this can lead people astray. If you are interested in diving, please approach a bricks and mortar dive store with proper, certified instructors, and do either a open water course (learn to dive with tanks) or a freediving/apena course (advanced snorkeling, learn proper and safe breathing technique for breath hold diving, a beginner can usually go beyond 2 minutes and 10 meters in depth with coaching, more experienced divers can hold from 4 to 6 minutes and go much, much deeper. )
The above item is a death trap for an untrained diver for a number of reasons. Namely, if an untrained diver runs out of air at depth while using this, then bolts to the surface, they are very likely to burst their lungs, because they have not been taught to breathe out while ascending. At least with drowning they can be resuscitated, if you burst your lungs it’s all over, with pink froth coming out of the mouth while you attempt to cough the shredded remains of your lungs out. not a very pleasant way to go. It is also dangerous for numerous other reasons that I wont bother to list here.
Conventional diving, scuba or free, on the other hand, is very safe with appropriate training. Australia and our near neighbours of indonesia, papua, etc have the greatest diving on the planet and i encourage you to experience it. Just please, seek training from a qualified instructor.’