My Wahl hair trimmers came with 9307A as an extra little trimmer, but it must have been meant to edge things only as it didn't come with any length guards.  I wanted to use it on my beard so I designed this set of guards ranging from 3mm-10mm.   They are model specific, but perhaps will be of use to someone else out there.  For putting them on, start at the back and then clip in the sides.