Product arrived on time and in excellent condition and my initial review showed no product defects. I am planning to use this for my concrete patio and the level of preparation for this will be amazing. I shook each level to burst the bubble and found it turned into a bubble immediately. I have noticed that there are a few small fibers in the traditional level fluid that appear to me to be very fine hairs or possibly glass fibers. They don't interfere with bubble movement at all and don't interfere with my indicator prep, so I still think it's perfect for that price.