AstromaniaLaser Collimator for Newtonian Dobsonian Marca Telescopes, Telescope Alignment 1.25 Inch 7 Bright Levels with 2 Inch Adapter, Great Telescope Accessory Laser Alignment Tool for Collimation

It is great, only the battery do not last.

Worked well right out of the box. Collimation of the laser beam was perfect and I liked that it had multiple setting for the beam intensity. Well worth the price.

I purchased this collimator, but was surprised that it did not include a battery. After reading the fine print on the Amazon website, I found that a battery was not included. After finding a CR 2032, I tried to install the battery, but found it was a hard fit. The retaining ring was very tight, and made it hard to screw down the battery screw plate. The paper work that came with the collimator did not indicate the battery type. Except for the battery problem, I found that the Laser Collimator work in collimating my 6 inch Celestron DOB. The adjustable laser brightness worked well with a setting of 3.

It came in a box and secure. The laser was very helpful to collimate the telescope. The laser itself was accurately aligned from the factory by testing it on my laser collimator testing setup. On target 4 foot away spinning it al around and ensuring the laser beam did not stay away of the bullseye.

I didn't have to collimate it. It was already collimated.

I have a 1981-vintage Odyssey 1 dobsonian scope and I've never used a collimation tool before on it. I knew it was not aligned very well, and I'm very surprised how quickly I was able to get the laser dot centered - it was like a minute and a half! The collimator fit the eyepiece mount properly and it was easy to angle it back so I could see it from the back of the scope. Then it was a simple and quick operation to use the setscrews to get the dot centered. It was so easy I'm planning to keep the collimator with my eyepieces and collimate every time I use the scope (which, since the mirror gets installed for every session then removed for storage after, will make for optimum performance).

Didn't come with a battery as advertised. There must be one company in China that makes these things and a dozen companies that slap their names on them. The laser is still weak which is disappointing. It was advertised as brighter and crisper... I dont see it. Even with a fresh Energizer battery. Well never hurts to have a spare when you have several scopes but temper your expectations.

Device appears to be sturdy and well-made. The CR2032 battery was easy to install, and the laser itself was easy to use. I installed it in the 1.25" eyepiece slot on my 6" Orion Dobsonian, following the guidance from Orion's YouTube video on how to do laser alignment with their telescopes. I had never collimated my telescope before. Despite being badly out of alignment, the process only took a few minutes to align the primary and secondary mirror. It's so easy I will definitely just check the mirror alignment every time now before using the telescope.If there is one nitpick, it is that I did not find the paper instructions included that helpful on their own. But combined with the Orion YouTube video, it was very straight forward.