Actually this company has taken the Via Aqua line of pumps out from under them so that Via Aqua has discontinued the line (such as the VA 305 now the NP-305), as well many for their UV Sterilizer products are far from the best:
http://aquariumopinions.com/2012/02/03/hang-on-uv-filter-review/
Even the AquaTop Canister filter, has some issues with leakage and are not the same canister filters sold by others that have made proprietary corrections to the same canister filter made by SunSun but branded by AquaTop
Even this company also does not make claims about the UV efficiency of these filters as AquaTop/TruAqua, as these are clarifiers at best
Reference:
http://www.americanaquariumproducts.com/ViaAqua750CanisterFilter.html
What I can also say, since I am in the business, is I have a friend who has been in the business for many-many years that they (AquaTop) actually attempted legal action against just because he was selling products that fit AquaTop products, but was only claiming that they fit, no different than an auto parts stores selling parts to fit a Ford that are not made by Ford.
As well a distributor I have purchased from was offered the original distributorship for their products, then he went around them less than a year later
BTW, I am not knocking all Chinese products, you're right, there are many good Chinese products, but I know from experience that there are good ones and bad ones.
As well many of these products are oversold on what they are, often calling a UV Clarifier a UV Sterilizer when in fact they do not have the proper dwell time, flow rate, and even use medium pressure UV bulbs instead of the much more efficient low pressure UV bulb
Reference:
http://www.uvsterilizerreview.com/2013/10/actual-uv-c-emission-from-uv-bulb.html
Often the same SunSun Filter is purchased and sold by one company with more filter material, or a submersible UV is sold without the prefilter, just to lower the price
