I have had some experience with thor M2s. Firstly, it is CRITICAL that you buy the version with a glass lens. They can be had for around $50 with slow shipping from china, or a little more from the US. here's a link, but feel free to look around.
(
here)
However, let me warn you that these lasers are FAR from perfect. Firstly, they are SERIOUS eye hazards, even far from the laser. mine measures in at around 1.5 watts. Although high power sounds fun, a 1.5 watt laser is 3 times over the class 4 limit, and one should really consider what could happen. Forget EVER using the laser indoors without high quality glasses, or pointing it around your yard. The dot should really be a good 20 feet away at all times for optimal safety. NEVER shine it in an area where there is any chance that the beam could strike someone. EXTREME care must also be taken when pointing this laser in the sky, if you are even willing to risk it. I would recommend the use of Flightradar 24(
Link Here) for optimal safety if you live in an area with heavy air traffic. I would also highly discourage letting anyone besides you even touch the laser.
Safety aside, these lasers can be a pain. The battery life is very short using the included batteries, and even with the highest quality batteries, the laser will never last more than 15 minutes. However the biggest problem with these lasers is the focusing mechanism. The laser is focused by moving the whole head up and down over the module, and after even a few minutes of use, the head begins to develop vertical play on the threads. This can usually be fixed with thread tape, but with this laser, the threads are not accessible. The only way this problem can be fixed is by locking the head in place by tightening it down, and setting the focus by adjusting the lens. That way, you can always return to a fixed focus that will not shift with general use. Of course, these lasers don't come properly focused at that position. This can be done with some patience and a properly sized screwdriver, but it is not easy and one wrong move could result in a scratched lens. Once you dial in the focus however, this is a pretty decent laser. The host is of decent quality, and feels good in the hand. The divergence is ok, and the tail switch is actually pretty tactile.
My personal recommendation would be to go on ebay, and purchase a laser 303. They are cheap(under $20), bright(30-100mw), and FAR safer. The beam is highly visible at night, and you can point out objects a good 1/2 mile away. They are safe enough to be used without glasses in most situations(NOT burning or objects), and will impress anyone new to the hobby. If you decide you want more, you can purchase a higher output laser, but I would give it at least a month to pick up proper safety habits. Also, be aware that these lasers emit IR alongside their visible green output, and if you get a low power unit, it may be emitting lots of IR that is just as dangerous as visible light. Despite this, these are still the best beginner lasers. My first green laser was a 303, and I was just blown away by the power. Take my advice if you will.
Note: If you are looking for cheap green laser with guaranteed output power, Sanwu is the place. I would steer you here in general, but you will pay a little more. I think it is worth it. Sanwu also makes very high quality handheld lasers that are far superior to anything on fleabay.
(
https://www.sanwulasers.org/product/304green)
If you must have a blue laser now, a good option is a $20 laserlands 5mw 445nm pointer. They are very safe with a true 5mw output. This laser is great is you are interested to get a feel for true blue lasers, and would also be a great start to a wavelength collection. This also the cheapest true blue laser I am aware of, and the seller is great.
(see it here)
One final option would be to get a blue lab laser. they can be had for around $50, and are a little safer being less mobile. I personally don't own one, so I cant report on the quality, but I would be dubious of the power claims. You will almost surely get 1watt though.
(
See one here)
I hope this helps, and I hope to upload some pictures if I have time.