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OK ,I am not familiar with the brand or the company although the EQ 3 mount is Chinese and of reasonable quality for the money.
You will find that the tube it is most probably Chinese and most of these are the same just in different colours.
For planetary use in an Achromatic refractor go for the longest focal ratio as possible.
Achromatic refractors suffer from a chromatic aberration problem which gives a blue purple tinge to brighter objects like the planets moon and stars.
The longer the focal ratio the less this problem is.
Also it is magnification prone as well meaning the higher you try to push the scope the worse the colour problem is.
80 mm f5 400mm fl achromatic refractors are great for low power wide field views but suffer badly from colour.
An f10 will be a whole lot better but not perfect for that you need exotic glass and $$$$$$.
A rough general rule is for a reasonable corrected achromatic lens you need the focal ratio to be 3 times the lens diameter in inches.This is only a rough rule of thumb.
There is a formular but it gets to technical for this forum.
Mark
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