An over pressurization relief apparatus having a manual over pressurization selector which allows a user to manually select from at least a first and second over pressurization limit. The device comprises a spark arrestor assembly including a base plate, a cover plate, and a spark arrestor. A first shift register storage element is for storing a signal received from the serial input and providing it to the serial output in a scan chain mode of operation. The power control information packet is received at a first mobile station. The present invention further relates to the use of the reactive dyes of the formula for dyeing substrates containing nucleophilic groups and to preparations containing at least one reactive dye of the formula.