IIRC, I have two that are at least three years old, and another bought the year after that. I only use them in the winter. Because my enclosure tops are aluminum screen, I bolt back of the RHP in a 1" thick foam insulation panel, and secure the t-stat probe in between. The foam hangs from the screen top, cinched snugly against it with wire.
I like the inexpensive Accurite probe thermometers too. They have worked for years for me with no display problems, and they all closely agree with other. Recently bought another set of four off Amazon (two new snakes), and a bigger one for the room temp in their quarantine space. All good.