Use: Water sensitive paper to check chemicals distribution. Yellow water sensitive paper turns blue where it gets wet. By placing a sufficient number of collectors over the plant, you can easily check the quality of the application by checking the evenness and regularity of the distributed solution. Optimum sprayer regulation increases the quality of the treatment, permitting correct distribution of plant protection products. Results: - Better chemicals application; - Environmental protection; - Less tank residue. Each bag holds 50 collectors (dimensions: 2.6 cm x 7.6 cm)