Holds 30 dropper bottles. Any 20ml dropper bottle will work. Even the older TurboDork pain bottles. You can find some here.

It screws into any Small Thread Hole part on the Multiboard grid system. I used a Small Thread Hole Snap and a bolt so I could move it around easily when adding more to my multiboard. They even stack seamlessly if you use any flush bolts. 

I printed on a dusty old Ender 3 so any printer will print this guy no problem. Photos show model printed with Transparent Purple PLA. 

No supports needed.