OMNITRONIC PA SF Housing F. Combo silver is a combo surface-mount housing for PA volume controllers and PA program selectors. It is constructed from durable aluminum and is intended for use with 100 V public address systems. The housing measures 8.3 cm in width, 5.2 cm in depth, and 15.6 cm in height. Its net weight is 0.40 kg. The product is finished in silver.