Brunton O.S.S. 10B Tool-Free

This is the least expensive compass with adjustable declination that I could find. I specifically got it as a cheap backup to my Suunto M-3D/L, and in that role, it has all the features one could want. However, apart from price and weight (1.3 oz, vs M-3's 1.7 oz), I find it distinctly inferior to the M-3, and would not recommend it to anyone as a primary compass, unless they were VERY price constrained.Specifically: The adjustable declination is done by hand-twisting the main compass relative to the outer scale. While vastly easier to adjust than turning the tiny set-screw on the M-3, I am concerned that it might just as easily go out of adjustment when banged around. It's also a little harder to set the declination accurately - or for that matter, even read the compass accurately, as the protractor ring's marks are a good 1/4" above the baseplate and compass needle, leading to parallax errors when looking at the compass from anywhere but straight overhead (vs the M-3's markings, which are almost flush to the baseplate).The 10B's baseplate is smaller that the M-3's, which makes it more compact and lighter, but which also means that it's a tad more difficult to draw lines and measure distances on maps. The 10B's needle is black on both sides, with N distinguished by a ring and S by a little 'arrow feather' indent - which makes it very hard to see the needle in dim light or against a dark background (vs the M-3's luminous needle, with the N side in red). Nothing on the 10B is luminous, and baseplate markings are in dark blue, which again make them hard to read in anything less than bright light. And, of course, the 10B lacks a magnifying glass (useful to older hikers like me), which all models of the M-3 possess.In short, the 10B is an okay compass - it points north, has adjustable declination, and is light weight and inexpensive, which is all one needs for basic use. No question, it's far better than cheaper compasses that lack a declination adjustment. But compared to the Suunto 3-M, it comes up lacking in usability. I wouldn't recommend it as a primary compass for anyone, and mine is going into the car emergency kit as secondary backup.

Got for my kids to start learning basic navigation. It's surprisingly hard to find a compass with adjustable declination for an affordable price. Basic navigation techniques - following headings, taking bearings (pulling from map and sighting one) are hard enough concepts for young or new-comers and having to adjust by adding or subtracting off declination makes it that much harder. It was easy enough for me to set the declination by swivelling the bottom of the bezel but it did not seem to slip as we spent part of our camping trip working with the compass. The Brunton Circle-in-circle is easy enough to use, and the simplicity made it great for my kids. Paralax isn't much worse than any other compass I've used. Bezel is stiff, but not hard to turn - fine if you ask me. Degree scale is big enough/etched dark enough to read but is crisp and clear enough to allow 1-2deg precision. Edges are crisp and clean, but corners are nicely rounded, so no sharp edges Fits nicely in hand. Etching on base plate is good -overall feels and looks like quality manufacturing. Whole compass is big enough for my kids to use/read/manipulate but not too big. Due to type of naviation I've done over, I personally prefer a sighting compass - lensatic or model with flip up mirror, but for simple compass for kids/novices to learn on, this was great.The CONs: First, one of the 2 I bought developed a small bubble (~1-1.5mm) between 8500 and 9000 feet which was not there at 5000 - not enough to cause any problems, though. Second, I noticed that when turning the bevel, if you do it quickly, it pulls the needle the direction of rotation, affecting your reading if you don't wait several seconds for it to re-align. I suspect it has to do with setting up a current in the liquid which has to calm down. I have not noticed nearly as much such lag on either of my 2 "expensive" Bruntons, my Silva, or my Nexus (or a $15 Brunton from 15 y ago - I dug it out to check). I'm used to working very quickly, though, and if I slowed down, it was not a problem. My kids didn't work fast enough to have it happen to them. You would need to be aware if this, though - I got some bogus readings until I realized what it was doing. I guess I could take off a star for that, but I like so much otherwise about these that I will go ahead and give 5 stars. (Anyway, if you are good enough to be moving that fast when taking map bearings or sighting, I suspect you would have skills and situational awareness enough to notice you are messing it up and would double-check and figure it out like I did.)

This compass has the features I look for in a navigation device at a price I can afford. It seems sturdy enough for daily use and I like the declination adjustment (though I had to watch a Youtube video on how to do it).I keep this and a local area map with me on all hikes even though I mostly rely on GPS. This doesn't need batteries.If Wishes were Fishes: I wish the text was glow-in-the-dark and I wish it came with a pouch.Overall: For the price I paid I am satisfied with what I got. I think it's a sturdy compass that is accurate and I expect to have it around a long time. If I find defects after I've had a chance to use it more I will report back here.

I love the clean compact design of the compass. I like the tool-free declination adjustment, the only complaint being it can be hard to adjust for someone who has severe hyperhydrosis. The item I received had a few scratches on the baseplate. Otherwise, it shipped right away and arrived a lot earlier than I expected. It is a very high quality compass for the price.

Nice unit. A little bigger than I expected (yep, I did see the dimensions), but it looks like a rugged unit. The instructions, while not really necessary, are apparently for more than one model, & this isn't very clear. If your a newbie navigator, get a good book.

I find this compass has to be held too level for it to work properly. Quite often I'll doubt the results and notice I haven't held it perfectly level enough. Could be better.

First, this compass works fine. My only heartburn with it is that it came with a big bubble in the fluid chamber. That doesn't effect the function of the compass, but it sure looks like heck. Nevertheless, not worth the hassle of returning and trying again.

Nice Quality. Precise & very useful. Worth it.

For the price it's alright. After 4 or 5 times being carried in a pouch in my bag the ruler numbers on the side were wearing off and a bubble appeared in the chamber. The bubble has since vanished mysteriously... maybe an issue with cold weather?The reason I gave this 3 stars is I have a compass from the dollarstore that is just as accurate if not more, and it doesn't get caught up on its axle and have to be wiggled around or balanced meticulously to find north.