The Model 33 used the seven-bit upper-case only ASCII code, also known as CCITT International Telegraphic Alphabet No. 5, with one (even) parity bit and two stop bits, with symbol rate of 110 baud. It was usually geared to run at maximum speed ten characters per second speed, i.e., 100 words per minute (wpm), but other speeds were available: 60 wpm, 66 wpm, 68.2 wpm, and 75 wpm. There were also many typewheel options. The Teletype Parts Bulletin lists 69 available Model 33 type element options. The type element was cylindrical, with characters arranged in four tiers, 16 characters per tier, thus capable of printing 64 characters. The character to be printed was selected by rotating the type element clockwise or anticlockwise and raising or lowering it, then striking the element with a padded hammer, which would accelerate the element against the ribbon and paper.