Manual colony counters is  used to count and record the number of visible colonies on a culture plate or agar dish. It has  a grid or lines to reduces the missing or double-counting colonies. This information is essential for studying the growth characteristics, reproduction rates, and other aspects of microbial cultures. It provide Counting pen to ensure no omitting of cells ,Multi-mode Petri-dish adapter .Compatible petri dish=50-90-mm; Dimensions=255x210x160-mm; Power=20-w; Counting range=0-999; Magnification=3-9-times;for more visit labtron.us.