Yes, Amazon's cheapest:
There are many different sellers of this same unit. I employ two and they even work in series with each other.
BUt at some point the LEDs just shut off. I wouldn't mind a little more range downwards, but the ability to dim at all, is awesome.
This link has good pics which shows the internals, but is not the cheapest available clone. I removed the bulky plastic housing to mount them where desirable.
I was not able to detect any difference between the 'prime' arrival and the $2.22 slow boat from china model.
http://www.amazon.com/Dimming-Controller-Adjustable-Brightness-Zitrades/dp/B007V1B0W8/ref=pd_cp_23_2?ie=UTF8&refRID=1AB9GGPGTTHT9BDZZB8DI also have a PWM motor speed controller rated at 10 amps which effectively dims LEDs and incandescents, and computer fans, but it is much bulkier.
I actually used the linked product to slow a 4 amp computer fan. When I used the higher rated 10 amp PWM controller, the heatsinks got so hot as to be able to burn my fingers when throttled all the way back.
The LED dimmer powering the same fan, throttling it back to minimum speed, without heatsinks, never batted an eye and if it heated up, I could not smell it.
I shoulda installed the pwm dimmer sooner. Love it.