JBL's MTC-14WG is an optional high-humidity grilles that's made to address the weakest link in high-humidity ceiling speaker installations: a steel grille that can rust. High-humidity grilles extend the life time of JBL's Control 10 Series White model ceiling speakers—Control 12C/T and 14C/T (both sold separately)—when used in such environments. It's constructed with an aluminum alloy material that doesn't rust, plus the durable powder-coated finish prevents pitting that could otherwise occur with raw, unfinished aluminum. The white finish provides a nice aesthetic, matching the speaker.