This clock has been patented by the U.S. Chess Federation. The large display and electronic accuracy makes your exact time and move number easy to read. This digital clock also features an optional audible tone and a red light to signal elapsed time. Delay option lets you deal sanely with sudden-death time controls. Start of each clock can be delayed at every move by a preset number of seconds, eliminating frantic and game-ruining time scrambles. Comes with a new feature called “Accumulate” where if a player makes his/her move before the delay time expires, the remaining delay time is added to their clock. Permits traditional time controls, without a delay.