I'm a newcomer to Sanwu lasers, but if this first laser from them is an example, I'll be a repeat customer.
I just got a 1W 520nm Guardian laser with the G7 lens and a single-mode click switch. It has the smooth case, well machined. The laser produces the brightest spot in the distance I've ever seen. With the 3x beam expander attached, the beam is about 1.5 cm wide at the laser, but the dispersion is less and it makes an even brighter spot.
First some pictures of the laser. It fits in the palm of my (large) hand, and is actually the smallest laser I currently have. It feels heavy, due to its solid metal construction. Although it is supposed to take an 18350 battery, it runs fine on 16340's.
As I said, the machining is excellent. Here are two photos taken from above. In the second, I slightly unscrewed the lens and the battery cap, exposing a tiny gap. When the ends are tightened, the gap is invisible.
I haven't taken any beam shots, and frankly they are never a close approximation to seeing the real thing. Take my word for it - the beam is brilliant, and the spot is clearly visible on any surface as far as the eye can see in bright sunshine.
Finally, here's a shot with the beam expander. With the expander in place, the beam is a thin ribbon which looks awesome in the night.
I also bought a set of star caps. These make interesting patterns on the ceiling, but I am unwilling to use them outdoors, as it's much harder to be certain that nobody is getting unwanted laser beams in the face.
Which brings up a final point. This is a dangerous device. I also own several powerful handguns and I also have a powerful drag race car. Each of these toys is dangerous and must be handled with caution, awareness, and most of all, respect.
Sanwu sent me a promotional pocket series laser, cyan. Total craftsmanship and wow what a powerful little guy. I've bought crappy 303's, and whatever the stupid looking barrel laser which runs off 2 16340 batteries. My tiny Sanwu laser running off a 10440 battery kicks all of their trash, has the brightest and most columnated beam, and the battery lasts.... well I haven't had to recharge one yet. Sanwu is highly recommended by me. Pretty sure they are going to be top dog in this niche market.