The silver SLIM 100E Expansion kit adds another 100 watts of power to your full SLIM 100W Solar Kit. As your need for power grows, so can your RV solar system by adding additional modules to your existing Solar Kit systems. Each Go Power! expansion kit includes a solar module, mounting hardware and expansion connections to quickly connect to the existing solar module on your RV roof. All Go Power! Solar Expansion kits are compatible with one another - 100 watts or higher.