I'm sure you're all thinking of the same thing: "What the hell is this doing on an airsoft BBS?"
Same thing. When my brother brought this... object home from Canadian Tire last night, the same mental process ran through mine as well. He said it was a pretty good deal for $24.95 + taxes, and that if it sucked, oh well, it was only $30ish gone. No biggie.
Comes with a button battery, screw-on rails for either standard 20mm or... the smaller one and instructions.
So, we mounted it onto my SIG 552, and here's the result:
Not bad looking I guess. Definitely clears my front sight, that's for sure, something my old Tasco RDS couldn't seem to do.
Here's a closer shot of it. Mounts nice and high, clears the front sight like I said before. Doesn't look half bad either!

And yes, that's a DVD of Transformers running
Once we put the battery in and zeroed the RD as well as a pair of noobs could, it was finished. The scope's glass isn't the best thing out there (and for $25, I didn't expect it to be great in the first place) as it's kinda dark (who the hell tints a lens that's optimized for darkness?) and a bit small for my liking. But it shows a dot, and it does its job.

Look! It's red!
The lens is a bit small, but once you mess around with it a bit, you get used to it, and hardly notice it after a few minutes. I don't know how it'll survive against direct hits, but I've heard that they've survived air rifles (probably the body, not the lens) before.
After loading up the guns and playing a little basement plinking, I found the scope to be pretty decent, and almost as quick to aquire as an Aimpoint replica or most other sub-$100 scopes out there. The tinted lens pissed me off at first, but then I considered this.
1: During the daytime, it'll make the dot easier to see in bright light.
2: At night, all I'll see is a bright ass red dot.
So then I was happy. Plus I really love the fact that I can't see my front sight anymore
Summary: Not a bad scope for the price. In fact, it's pretty amazing for that price. It does the job, nothing more, nothing less, and does it quite good if I must say so. Plus, it's cheap as balls (compared to most RDSs out there) so you don't have to cry when a BB shatters the lens. All-around, it's a good performer which gets a 4/5 from me.
Pros: It's cheap
Good for rifles with front sights and low mounts
Easy to use, adjustable on the field
Compact and light
Cons: It's cheap...
Power button sticks out a bit... might get snagged on something and
turn on/off by accident
Lots of plastic parts, could snap/break off
Possibility of getting the lens shattered by a good shot
Hope you gleaned something useful from this review!