WSB QUICK MARKING SYSTEM ( 249-557) is a must-have accessory for efficient organization in any industrial setting. Its sleek white design and snap-on mating type ensure easy installation on barrier terminal blocks. The black marking color stands out clearly, meeting UL 94V-2 flammability rating standards for safety. With a non-stretchable 5mm width, these markers are perfect for horizontal numerical labeling. Enhance workflow and compliance with this essential tool for marking barrier strip jumpers, covers, and terminals. Stay organized and efficient with the WSB QUICK MARKING SYSTEM.