I used "some kind of" because they are some kind of. The cylinders are refillable felt markers withs different felt-tips. some flat, some round, some 5cm large, some normal felt-marker tips. even the grip of the markers is of different diameter. The thinnest is 3cm in diameter and the largest is 4,5cm in diameter. They are all about the same length +/- 10cm.
hope that explains better what the objects are.