www.uischoolsupply.com sells Sand Timers Combo Pack by Teacher Created Resources. (TCR20663)

Race to see how much can be accomplished before time runs out. Great for games, timed test, and time management. Combo pack includes 1 each of 1, 2, 3 & 5 minute timers. Handy plastic timers with colored sand. Includes suggested activities. Each timer measures 1″ x 3.5″.