Today I got the hand pressure sprayer and immediately tried. Only a "cold start" with water, then with the agent that I wanted to spray. The delivery went smoothly and quickly. The spray result is relatively good - just as one would expect with such a cheap product. A small disadvantage - marginally - however, there is: one must constantly re-inflation. Therefore, only 4 ****. The pressure can not be built so high that he would, for example, rich. For half a bottling or so. An overpressure can not occur and I therefore wonder if the "pressure relief valve" which could withstand all. But as I said, it is an inexpensive, not to say cheap, product and ensure it is perfectly fine.