Paterson Chemical Stirrer .

A stirrer for mixing darkroom chemicals. Simple thing, but worth having a dedicated one.

The flat end works as a particle crusher — if you're mixing chemistry from powder and there are undissolved crystals at the bottom of the jug, you press and roll to break them up. That's more useful than it sounds. Undissolved chemistry causes uneven development.

It's long enough to reach the bottom of a 1200ml graduate, chemical-resistant, and won't contaminate your solutions. Keep one by the mixing area.