Labtron manufactures the Manual Colony Counter for microbial colony enumeration on agar plates in microbiology, food safety, environmental, and pharmaceutical laboratories. It counts from 0 to 999 and supports Petri dishes measuring 50 to 90 mm. A dual-rack design enables simultaneous handling of two plates, while 3× to 9× magnification and white LED illumination assist colony differentiation. A 3-digit LED display, audible count confirmation, and pressure-sensitive marking pen support manual counting and result verification.