A device for the visual indication of liquid flow. Flow indication is visible up to 25 ft or more away from the unit. Usable with water down to a flow range of approximately 100mL/minute, which is adequate for even the smallest cold finger condensers. The upper flow limit is in excess of 1L/minute. Speed of ball rotation is a semi-quantitative measure of water flow. Unit operates in any position. Molded of clear polycarbonate with an inert red nylon ball. Light in weight. Requires no auxiliary support. #1 hose connections.