Each screw-top jar can contain 1/2 oz of liquid/ink
Size: 4-Rectangle (4 jars): 1.5"x6.5"
The bases are made so that the jars fit tightly in their holes, but also made so you can remove the jars. To remove a jar, you might need to wiggle the jar back and forth while pulling. It can take some effort. Of course, you will want to make sure the lid is screwed on well before starting to remove the jar. When replacing a jar -- if you want it to be removable again -- push it into the hole just enough for it to be secure, but not as deep as it will go.
Jar inside dimensions: approximately 28mm dia. x 25mm high