I've only tried out the Barlow terrestrially but so far so good. FLO's service is excellent as usual with a very quick delivery. I wish you guys would stop hexing the weather with your "May come with clouds" stickers... it's been cloudy most nights since September.🤣!

Top shelf perfermance with my Orthos/Delites on planets usefully the bottom Barlow element screws off to become a1.3x Barlow when screwed onto other eps..Bear in mind it will not work at 1.3x in some eyepieces with an internal barlow which are low down under about a half inch from their barrels preventing the 1.3x from screwing in..but say in my meade 5.5UWA which has an internal barlow it works a treat..so pot luck with some eps its not the fault of this wonderful Barlow just different ep with these built in Barlows can sometimes have very low elements in their
insertion barrels preventing usage at 1.3x..most 1.25 inch eps will work though... at 2.25x its marvelous ..like it better than my less useful vixen 2x that only stays at the one magnification!

Small and light, so far only used with zoom eyepiece. Only used as a 2.25x barlow. It is easy to use, very sharp image and hardly noticable reduction in brightness when looking at reasonably bright objects

Three-elements achromatic barlow. Works best with short f.l. eyepiece, very sharp on-axis with my 7mm Ortho.
The 1.3x element magnification is usable only in eyepieces without an internal barlow element (you should have enough space in the barrel).
The barlow will not work with medium f.l. widefield eyepiece (it vignettes).
Overall a good but specialized product.