Zack Marker strip. ZB marking system provides logical and clear identification of modular terminal blocks and interface modules. The 10 section ZB marker strip can be divided conveniently at any point. -40 to 100°C operating temperature. This label combination consists of a strip of 10 labels printed vertically with the numbers 41 to 50. Easy to apply (push into grooves of terminal block). 5.2 mm pitch.