This by far is the best focal extender in my collection. Flat from edge to edge with no image distortion. By far worth every penny. I will enjoy this extender for years..

I have a Explore Scientific 127mm triple refractor which is f/7.5 The 3 field flattern reducer increases my telescope speed by decreasing the f ratio to about a f/5.2 and gives sharp stars to the edge of the field in my photographs. The item works perfectly with my Explore Scientific telescope.

I have the removable dew shield ES127ED APO model. I unthreaded the 3 barrel and used the Adapter 1 to thread the flattener/focal reducer directly to the focuser drawtube. I then threaded my SBIG ST2000xm to the front of the FR using the CCD camera adapter t-threads. The star field is tack sharp from edge-to-edge, no aberrations.

I paid Only 99 dollars to get this FExtender w/4 optical elements, cause it was on discount!. Thanks B&H for that! Quality is superb and after a few weeks I am pleased with buying. I have improved my observation and photo/video capacity of my Comet Hunter. Great job of Exp. Scientific with this 2X extender. Highly recomendable.

I have had nothing but cloudy weather every since I purchased it.
Tonight however I had a very short window to give it a try. I used it in conjunction with an Explore Scientific 14mm 82 degree field eyepiece as a test. Viewing Jupiter through my 6 inch Celestron Evolution telescope the 14mm gives me 107x. The view was very sharp. When
I added the 2x focal extender the view of Jupiter lost no sharpness or contrast. Magnification was now 214x on a very average night. This is the best by far of a variety of 2x Barlows that I have used over quite a long period of observing.

I ordered this product to multiply magnifications of my eyepieces. I tested it for planets and double stars at very high magnifications, and really like the product. The green color coating looks great. I think $ is a bargain for a four element 3x barlow. B&H shipped really quickly. Overall, I like the B&H service and price, and I highly recommended this 3x barlow.

There are many A+ reviews about the 2x Extender from Explore Scientific! Add my opinion as A+. Okay, so the glass is excellent and the machining of the unit is exemplary - fit & finish unbeatable. What puts this above & beyond are the instructions are easy to read & understand, and the box from ES is an amazing work of art and utility! Seriously! The box alone is probably worth keeping & displaying at any gathering! The extender is hefty and is packed well within; a given. The covering is based on Wil Tirion's Uranography & Graphic Design! My wife was more impressed with the boxes, than the gadgets! Guys, ponder it. I may survive this purchase. LOL!

This is a amazing piece, you won't be disappointed with it. It is heavy, but worth it. A nice way to get more performance from your 9mm eyepiece on clear seeing nights. It comes with a 2 to 1.25 adapter as well. I picked up a separate 2 plastic plug so I would not have to use the metal adapter as a plug on the female end.

I've only run one night with this but from what I can see, there was no degradation of visual or photographic by putting this into the optical path, the build is rock solid.

Excellent field flattener and focal reducer for my Explore Scientific ED152 refractor. A must have for doing astrophotography!