Usage Tips:Optimal Dimensions for Visibility: Measuring 4 x 2 inches, these lightweight and compact label holders are designed to be space-efficient while maintaining clear visibility. Their classic design is unobtrusive yet functional, making them ideal for a variety of settings from classrooms to warehouses. Strong Magnetic Backing: Crafted from durable, soft rubber magnetic material, these label holders provide reliable adherence to any magnetic surface without slipping. Their ease of repositioning makes them perfect for dynamic environments such as classrooms, workshops, or retail spaces. Easy Installation Process: Installation is a breeze-simply write on the paper insert, slide it along with the protective film into the holder, and attach it to a magnetic surface. The C-channel design allows for quick labeling and relabeling, saving valuable time and effort. Versatile Use in Various Settings: Perfect for labeling metal shelves, mailboxes, lockers, and file cabinets, these magnetic label holders can be used in schools, offices, retail stores, and more. They facilitate easy identification, enhancing efficiency and organization wherever used. Quantity:50 Sets/30 Sets Colour:Black & White Material:Rubber soft magnet Size:About 100x50mm Package Contents: 50 * Magnetic C Channel Label Holders 100 * white label cards 50 * clear PVC covers / 30 * Magnetic C Channel Label Holders 60 * white label cards 30 * clear PVC covers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.