It marks, counts and even gives an electrical beep to let you know each colony has been counted. This lightweight, compact, pen style colony counter reduces the likelihood of error by combining all aspects of counting into one motion with only one hand. Features an easy to read 4-digit LED showing cumulative count, selector switch for counting up or down, (Correct errors or check count), long life black felt tip pen. Works on plastic or glass and has a replaceable 3V battery.
