Yellow   sally stonefly nymphs are available much of the year, but more active during   warm summer months.  RIO's My Gal Sal   has a pale golden yellow belly covered by a dark brown and copper back tied   on a Gamakatsu hook with a tungsten bead.
   The following are the bead sizes per hook:
Size 14 - 3.3 mm 
Size 16 - 2.8 mm