You can find it here. Learning resources also features an Elapsed Time Set that has magnetic strips that show the passage of time. You can find those here.
Another helpful resource are the Magnetic Elapsed Time Bars sold by "Really Good Stuff". These bars show comparisons between segments of time (think fraction bars) in a very visual way. They are made of durable foam that is backed with magnetic strips - perfect for use on a white-board or refrigerator. Those who are teaching using the Singapore Method will like the way that these bars approach elapsed time problem solving. You can purchase them here.
I purchased each of these products myself. I am not affiliated with either company, and I did not receive any compensation for this post.