This set of shelf hardware includes one hanger bolt, one wingnut, and two washers.  The hanger bolts are 2" long.  The washers are 1 1/2". 
This hardware can be used to attach wooden shelves to your cage.  To attach a shelf so that it is stable, you will typically need at least 2 sets, possibly more depending on the length of the shelf.
Please note: the wooden shelves we sell all INCLUDE hardware.  This listing is for hardware only -- for if you want to make your own shelves.