I have bought both the RC56 and the Pacer 560. As far as I can tell, they are both the same stuff. I just bought what was available at the time. Great stuff because it comes out white so that you can see where it is going and it dries to a clear finish. Don't expect a quick dry time. The stuff takes overnight to dry if you have a thin layer and may take a day or 2 if you are using it to fill in larger gaps. Once its dry it sticks great and stays flexible. I use it to stick small pieces of fuel tubing to the sides of the fuselage on my planes to run my antenna wires through. I also use it to hold balance weights in place both in the wing and in the nose or tail if needed.
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