If you can buy it at your local hardware or home improvement store. Don't use it on the outside of the camper or RV. Products that are designed for use on "static" buildings will not properly adhere or flex with your camper or RV.
The caulks designed for the RV world have very different adhesion and elasticity properties.
Campers and RVs "flex" has they travel down the road. Standard Silicon Caulks will not stretch enough and will pull free creating a water channel. Often times you will end up with more of a problem than you started with.
I recommend the Geocel Pro Flex line of caulks. They work on almost any surface and have excellent adhesive, elasticity and Anti-UV properties.