Works as a level, but the hardware to fit it onto the picatinny rail is not the greatest. It is not designed as such to let it grip the rail firmly. Granted the rail it was attaching to is an aftermarket rail so there could minor manufacturing differences, but other attachments have had no issue and this one could not be made to squeeze the rail before it bottoms out on it adjusting mechanism. Just be aware some modification may be needed.

Installed easily, does the job.

Simple and effective, I will never go back to the multi level systems. Follow these steps.

1.Attach level and level rifle
2.tape a piece of paper to the wall and using a level draw a verticle line with fine tipped pen
3.turn scope to max magnification and rotate out the eye focus lense (part you look through)
4.shine a flashlight through the objective lense (lense that's towards the front of the gun)
5.match the verticle line of your reticle with the line you drew on the wall

Sadly many people level the scope body but your your reticle might be off in the scope. This ensures that the actual reticle is level and it's super easy. Never again will I waste time balancing multiple levels on my rifle and scope. This is easier and more accurate.

As an ELR shooter, frequently working at ranges well in excess of 1000 yards, it is important to avoid any cant of the rifle/scope system. Anyone looking at this level knows the importance of maintaining a repeatable scope level. I use this level on the Pic rail of my rifles as the primary reference for rifle/scope setup and leveling, and lets me verify a scope is properly re-seated on a QD mount system (after I level the reticle against a reference line, I install a second level on the actual scope body to match the bubble on this level mounted to the rail). This helps me hold the rifle in as repeatable of a position as I am capable at different firing points. I like this level very much, quality is definitely "5 Star" worthy, but as to the whole system, I withheld one star because this model does not engage the slot in the Pic rail. While I've never had one come loose, I'd prefer that it engaged the slot on the rail. For me, that would make this very good, reasonably priced level into an excellent 5 Star item.

Excellent quality in aluminium and black finish to suit my Steyr blued rifle piccattiny rail.
I bought it in good faith as some similar items are in plastic but this was just what I wanted.
Assembly quality and finishing is excellent.
Accuracy is Good and it fits and locks well onto the rail.
I am pleased with this item and may buy again for myself and others as friends will see it on the range today.