Snap Circuits UC-80 Upgrade Kit SC-500 to SC-750 (INCLUDES CI-73) Get the additional parts and manuals to take your Snap Circuit Kit to the next level UC-80 Converts Snap Circuits SC500 into Snap Circuits SC750 Includes 10 new parts including, CI-73 Computer Interface and a solar panel 250 more projects Part of the extremely popular Snap-Circuits educational electronics series from Elenco Electronics