These solid heavy duty lugs nest when not in use. Fits dolly, item 60592 for mobility (sold separately). Gray Lid, item 60596, make these stack when you have more than one. (sold separately). Available stock colors are red, blue and gray. For Green or other custom colors min 250 qty. and set up charge of $500.00 - See page 189 of our 2011 catalog for details.