Designed to fit any developing tank cap, the Tank Top Timer from CatLABS is a conveniently sized temperature-compensating developing timer. This timer produces a tight seal that makes it suitable for inversion agitation and doubles as a digital tank thermometer with accuracy to 0.1 °F. This precision stainless steel timer features a single button for simple use and ultra-low power consumption, with an average lifespan of 5 years on a single CR2032 coin cell battery.

Standard Ilford time-temperature tables are utilized for accurate developing times.