Works great. Nice to know your optics are perfect vertical and horizontal when mounting. Having your optics where they should be makes a big difference on accuracy.

Buen equipo

The one small level arrived with the level vial broken loose from the aluminum frame. The other pieces seem okay. As others mentioned you do have to calibrate the levels yourself.Edit - Great customer service! Knine outdoors reached out to me and sent a replacement very quickly! I would buy from them again.

Got this because I had a couple of new optics to level, and boy is it a game-changer from using hardware store levels to try and get your optic properly installed. And on rifles with a short optic rail that is covered by the scope mount (or no optic rail at all), it is absolutely necessary to have the barrel clamp level that you can adjust. The small levels can also be adjusted if they are a bit off, so that you can be sure that everything is accurate, using tiny set screws on each side.Basically, I didn't find anything wrong with these, they do the job, and are a bit cheaper than some others out there. I can't speak to the absolute accuracy of the machining on the aluminum bodies of the levels, but since they're adjustable, you can test by reading it, then spinning it 180 degrees and seeing if the readings match. If not, use the set screw to get it exactly where it matches in either direction, and you're good to go. The small levels are also magnetic, so they stay in place on your rifle's rail or the open turret of your scope. About the only thing I could wish for is for them to be a bit clearer to read, as light can play a bit funny in the liquid and you can get a bit of glare off the unfinished aluminum bodies of the levels. Another minor complaint is that the two small levels don't match exactly with each other as far as the amount of bubble and the centering of the lines. But since they each read properly, they don't have to exactly match each other, and you'd only know if they were side-by-side. But for this price, that's a lot to ask for. Overall, works great!

I have also owned the very similar gold colored Wheeler scope leveling tool for a few years and will compare with this new KNINE unit, solely purchased for the additional quality, adjustable small block levels.The out of the box experience for the more expensive Wheeler unit is superior, as its small, block level is factory calibrated and immediately usable; I would give it an Amazon rating of 4. The Wheeler storage case is far superior to the simple cardboard box of the KNINE unit. Both OEM units seem identical in construction and materials and could have been produced on the same assembly line and seem to be very good quality.KNINE supplies a hex key for level adjusting and Wheeler does not. The KNINE levels were NOT LEVEL as delivered and not immediately usable. The KNINE supplied hex key also fits the Wheeler level. The silver colored KNINE units level bubble is much easier to see than the darker brass/gold colored Wheeler units due to the lighter color of the silver KNINE units. The KNINE unit supplies two small block levels where the Wheeler only supplies one block level. I find it much handier to have at least two block levels, which is why I recently purchased the KNINE unit for the additional small levels. Both OEM's block levels have good, strong, hidden magnets inside their bases.Neither OEM provides the slightest hint of instructions of how to level their block levels and I found this process frustrating and very time consuming. One does not need a level surface to verify a level bubble, as simply when swapping the level end-for-end, the bubble should stabilize at the same place each time, which would indicate level. Otherwise, if the bubble locations do not match when swapping end-for-end, the level is not level. However, I found it easier to use a small piece of granite set on a work table top, which I leveled using wood shims and a relatively level torpedo level, as a reference work surface for adjusting the new KNINE levels.I would have thought that simply raising one side of the level and/or lowering the other side would adjust the level equally and find equilibrium relatively simply. But that WAS NOT my case. I tried releasing any tension from both sides and then adjusting one side or the other to get a proper bubble level set and that failed to work from either side; it all seemed to be operating backwards at times and then opposite of that at other times. Obviously, I did not have a grasp of how they attached the adjusting screws.Very long story short, I THINK what I finally did was to provide moderate upward tension on each side of the level to get relatively close to a level bubble and then released a small amount of tension on one side (or sometimes both sides) and/or increased tension on one side or the other and FINALLY got the levels level. It was NOT an intuitive process as I did not know how the adjusting screws were installed/threaded to each piece and how they operated together and independently as an assembly.I have dropped the small level of the Wheeler unit a few times, and over time it has lost its level a small amount. I had similar adjusting issues with it but was overall easier as its bubble was not far out of adjustment.

Honestly for the price these are great. Key is the levels need to be calibrated before use. I have a digital level that is very accurate make sur have a known level surface use the adjustment screws to center the bubble on each of the small ones comes with a small allen to do so. Once you do that they will be accurate use the two small ones to level rifle then install the clamp level on the barrel use adjustment screw to match level again good to mount your scope. Works well if you follow these steps. This tool works as intended no need to drop more then $20 or so on this type of system