My friend Chris Abbott gave me this a while ago. I’ve been meaning to mention it here (and thank him publicly). I used to live in fear of spilling the flux used to prep wires for soldering. I also used to drip flux where I didn’t want it as I transferred it from bottle to project on the end of a piece of wire.
This bottle – I think Chris found it at an electronics supply house – keeps the flux inside, even if it falls over. And the needle cap (with cover) is brilliant: a gentle squeeze deposits one drop of flux exactly where you want it.