The ABS-1TB(C) is an attractive surface-mount backbox for mounting one ACS Series Annunciator. Unlike the ABS-1B(C), the ABS-1TB(C) has an increased depth that allows mounting of the AKS-1B Annunciator Key Switch. Black, 9.938" (25.24 cm) high x 4.625" (11.75 cm) wide x 2.5" (6.35 cm) deep.