Sliding-Rheostat-for-Senior-&-Middle-School-RVFM-P04030-This-sliding-rheostat-is-ideal-for-use-in-the-classroom-&-the-laboratory-by-students-in-Key-Stage-3-&-Key-Stage-4-The-rigid-open-framework-ensures-protection-&-cooling-for-the-electrical-circuit-Sliding-Rheostat-6-3A