1/4" Collet & 1/2" Collett came with the package. I am UNABLE to keep the 1/4" bit tight enough in the collet to use. I suspect Collet is metric? The sleeve talked about in manual did not come with the package. I'm thinking I either need a true 1/4" Collett or this sleeve. In my browseing I found two items that may help (holding Clamp 1/4" F67407 & Clamp reduction 1/2-1/4 F67414) but dont know because can not find enough info or find a way to order it.