This is a chemical resistant trigger used in the car cleaning trade for spraying alloy wheel cleaner, traffic film remover, solvent glass and any other chemical based products, see the chemical resistant bottles in our shop. Triggers will normally last a long time depending on usage and the chemicals been used. If the triggers stop working please immerse in warm soapy water to soak for a few minutes Then keep pulling the trigger until air or a stoppage has been removed. Very often the fine filters inside get corroded especially when using corrosive chemicals. Once unblocked the trigger will work again