I just received the elusive Brunton button compass from Barry @ Blueline. They are exactly the diameter of a penny. Metal objects easily affect readings : not that Id conduct any survey with one. What we have is a decent quality addition to a PSK for keeping to rough headings.

Hmm. "Exactly the diamter of a penny" (.720"?) is actually quite a bit larger than the Sun button compasses many of us have settled for so far (about .520") (ok, so I just happened to have a micrometer sitting on the desk...), almost a 40 percent increase in diameter ... volume/mass probably going up at about the cube of the increase in linear dimension, that's... well, more difference in size than it sounds like. I'm surprised, I thought Brunton had one still smaller?<br><br>I wouldn't want to call in an artillery strike with any of these...<br>