Anyone have any info on these? They look exactly what I am looking for. 4" powered monitor with bluetooth for $130. I am skeptical because I can’t find any info on them and they are almost too good to be true for the price.
if your expectations are: 4" monitor with bluetooth and 130$" and nothing more.
They probably are just that. 
They probably aren’t that much different from the rest ~150$ BT monitors… I mean i bought the Mackie CRT5 BT and… well after 10min they found their way in my concrete garage. They actual have some bass… when being intimately close to the back wall in a small bunker type of space. Other than that… i mean compared to proper monitors… they are shit. Just shit.
Only goods thing are: after 4 years in dusty and sometimes bit humid space , they still work and were cheap.
For background noise productions they are very good and do that.
Have not heard those and don’t know anyone who has so I cant speak to the Dyna4 or anything from Donner. Looking at them online they have a lot of “features” that you would not typically see until 2 to 3x the cost. It’s hard for me to fathom that they can pull it off at $130. Their music gear (guitars & bass etc.) are all very, very entry level so perhaps I’m letting myself be tainted by that unfairly.
Have you looked at the Edifier R1700BT or R1700BTS (S is for subwoofer out)? They actually sound really good for the price point if it is just desktop speakers w/bluetooth you are looking for. I have two sets of the Edifiers so I can speak to those. Are they super high-end nope, but they sound really good nearfield and with good tonality IMO. I used to have them on my main desktop with an Atom stack, and I still use that combo in my work from home office setup.
I have been looking at the Edifiers. In fact, they were the first ones I was looking at due to all of the good reviews. I will probably just go with those as the safe choice.