Equatorial Ring Sundial

Designed by the man who designed the Slide rule.

[@gowrimanoharidhanasekaran9236]

Quite cool

[@smilehappy3112]

I looked at this video because someone was selling it on offer up for 35$

[@RCFlyBoy314]

They are still made! They go by brass pocket sundials as well. $35 seems to be a decent price