2x2cm Solar Cell in a White Plastic Case with 6-inch Red/Black Wire Leads (stripped ends).
The factory has tested this 0.5volt, 2 x 2 cm cell in 1 sun conditions and written the output on the rear of the #2 size plastic case (2 1/4" x 1 3/8" for reference).
Since a silicon cell is used, the current output is almost linear to the amount of light. Example: 1 sun = 125ma / 50% sun = 62.5ma
More information including spectral and intensity response graphs, series/parallel circuits, and an average solar irradiance map are also available here: Intro to Solar Energy