The Baby Blue light is a compact ultraviolet light used to detect bag leaks in dust collectors. The baby blue ultraviolet light detects leaks in individual bags or welds by highlighting an ultraviolet pigment called Dust Chaser is introduced into the ducts before the dust collection system. This dust will escape where there are leaks present. After introducing Dust Chaser into the dirty air stream, you take the Baby Blue Light and shine it on the bags or ductwork to quickly identify any leaks.