This is the Fluorescent Green Acrylic Rod 3/32 x 10'' (8 pack) from Plastruct.
A unique additive in the Acrylic actually gathers light from the sides of the rod and emits it from the ends. Originally developed for education, creative modelers are finding many other uses, including switch lights, auto tail lights, candles and neon signage. New Acrylic formula allows flexibility on 1/8 (3.2mm) and smaller size rods not known to Acrylic Plastics. Precision Extruded in Blue, Green, Red and Yellow Fluorescent Colored Acrylic Plastic.