The System 300 S model was the academic version of the System 300 model which had been introduced by Braun in 1969. The 300 S first appeared in the price list of 1971-MAY-01. The 300 S model replaced the 300 model and included the A5 format 1200 Schaltalgebra Lehr-und Lernkartei (teaching and learning cards) documentation along with the LN 300 power supply (Netzteil).

The System 300 S was the only S model to retain the original white packaging box rather than being changed to the light blue color box.  This is a very rare model to find!