Wordlock, a combination lock using words instead of numbers, were created by Todd Basche, a Silicon Valley executive. Sold by Staples for $5.98 (in blue or black) or $3.90 (in orange), it consists of five independently-rotating rings, yielding one hundred thousand different positions, any one of which the user can select. Because words are more easily remembered than numbers, he inscribed four of the rings with ten different letters each, and the fifth with nine different letters and a blank, allowing the user to pick either a four-letter or a five-letter word.
Eckler, A. Ross
"Word Networks on Wordlock,"
Word Ways: Vol. 39
, Article 15.
Available at: http://digitalcommons.butler.edu/wordways/vol39/iss4/15