Hi antoj, It looks like the image you are referring to is from the owner's manual that came with your 8240 tool. The diagram illustrates the markings on the different size collets. Three lines on the collet means that it can accept accessories with a 1/32" shank diameter, 2 lines is a 1/16" collet and one line is a 3/32" collet. This is a reference diagram and it does not mean that the collets are included with your particular rotary tool. Your tool includes a 1/8" collet and it has no lines on it. Dremel is making more and more of its accessories compatible with the 1/8" collet and fewer accessories will even require the other-sized collets. These other collets: models 481, 482 and 483 do come in handy when using any accessory that has a shank diameter that is less than the standard 1/8" diameter. Examples of these accessores inclue drill bits that have a shank diameter the same size of the hole that they drill. The outside of the tool package is your best indicator of knowing what accessories are included inside the tool kit. I hope this helps!
