Most digital wristwatches include countdown timers. The Timex Ironman series is very popular, useful, and not very expensive, plus you will get much more than a countdown timer.
Casio make digital watches. Most have standard features like a stopwatch and an alarm. Some have countdown timers and these are good for short sprints.
As per my opinion and experience Godrelish Electronic Technology company that makes good countdown timers. This company timers has many options for selecting the background and font size of numbers.
It depends on if you need a desk timer, say for exams, or a hand-held for sports. I found that Robic makes a good times for sports. They have a number of models available. Accusplit has a great desk timer with easy to read display.
