Nu-Calgon 4148-32 Cal-Shield Coil Surface Protector is a water repellent, non-toxic, and non-flammable surface protector for coils. It is a two-part system that includes a spray bottle and a coil cover. The spray bottle is used to apply a thin layer of the protector to the coil cover. The coil cover is then placed over the coil and secured with the included screws. The Nu-Calgon 4148-32 Cal-Shield Coil Surface Protector is designed to protect the coil from water, dirt, and dust. Nu-Calgon 4148-32 Cal-Shield Coil Surface Protector is a water repellent, non-toxic, and non-flammable surface protector for coils. It is a two-part system that includes a spray bottle and a coil cover. The spray bottle is used to apply a thin layer of the protector to the coil cover. The coil cover is then placed over the coil and secured with the included screws. The Nu-Calgon 4148-32 Cal-Shield Coil Surface Protector is designed to protect the coil from water, dirt, and dust.