Surface Mount Back Box Pattress Box 1 Gang 32mm Single Gang Deep Wall Mount. This back box is designed for surface mounting and is a single gang, 32mm deep. It conforms to BS5733 standards and has threading holes approximately 6.5cm apart. It is also available in other sizes such as 16mm, 25mm, and 45mm, with some variants including a cable holder. The brand is Kenable. SKU: 007484, EAN: 5055383474844.