to meet the most demanding professional Public Address application. The panel is made of high impact ABS plastic. With panel size equivalent to MK 1 gang plate ( 86mm W x 86mm H x 15mm D ) for installation in standard flush or surface mounting back box. The output sound level is adjustable via the rotary knob with 6 steps of output level attenuation. Provision of an emergency overriding relay (24VDC) allows paging / announcement to bypass the selected volume setting and automatically set the sound output level to the maximum.