what does triplet mean?

what does triplet achromat mean? and is that a good thing vrs doublet or whatever is standard on a refractor?

There is a third lens element (as opposed to the two in a doublet lens) to further correct for chromatic and spherical aberrations which could otherwise be fairly severe in an f/6 refractor such as the scope just discussed.

An achromat is typically a telescope that focuses two light wavelengths to the same point whereas an apochromat is a telescope that focuses three to the same point, the objective being to remove chromatic abberation (ie. false color). A doublet is a lens with two elements and a triplet is one with three.

Most standard refractors are achromatic doublets whereas most high end ones are apochromatic triplets.

this triplet achromat use a doupletwith close airspace and a rear lens in same same with a bit wider spacing. Correspondance to the manufactors infos this help them to get a bit flatter field and do a bit better controll on chromaticle aberration.

Personaly I do not offer it as a high end scope, but as a nice widefield scope. In germany its far less expensive than a Skywatcher 102/500 douplet, espacily our chinese made version comes with rings, 50 mm finder, 2" diagonal and a Plössl eyepiece.

Its a good scope for low power wide observing and black and white imaging.

Today a german customer who got such a baby reported he used it also for Planets with good results

best wishes
Markus