Have you ever bumped the tail on your plane while it is on the work table and had it try to roll off the edge? How about the way they move when you are trying to make an adjustment?These wheel chocks will keep your model safe on the work bench , flying field table or while being displayed at the model show. If you are working on your model in the grass they double as a cup to hold small screws or other hardware. The chocks are made with clear tough PETG plastic and can be painted from the inside for good visibility or leave them as is so they are less noticeable. Do you hate to put those paper dots on your model that the contest director gives you to identify your model? now you have the perfect spot.