rubee is 99.99% magnetic waves it therefore is not affected at all by people or animals, mud or water. steel can alter performance, but steel can actually enhance a magnetic signal. a high frequency (over 1 mhz) rf antenna on or near a steel shelf has three problems: 1. the steel detunes the antenna; 2. rf nulls will appear on the shelf with no signal at all (swiss cheese field) this is because steel blocks radio waves; and 3. steel also reflects the radio waves (e in maxwell's equations) contributing to communication errors and shelf nulls.