Product: Standard jumper caps (pack of 50) Model / Size: 2.54 mm (0.1 inch) pin spacing Color: Black Material: Insulating outer plastic with internal conductive contact Package: 50 pieces What it does and why you need it Simple, reliable way to open or close electrical connections on circuit boards and interface headers. Installing a jumper cap bridges two adjacent pins to create a closed circuit (ON); removing the cap leaves the pins open (OFF). Saves time and reduces errors compared with soldering or wiring when changing device settings or configurations. Reusable and compact for repeated use during testing, development, repairs, and system configuration. Key benefits Compatibility: Fits any standard 2.54 mm (0.1 inch) header used on motherboards, hard-drive jumpers, computer interface cards, and many development or control boards. Ease of use: Push-on design requires no tools; quick to install and remove for fast configuration changes. Safety and insulation: Outer plastic body insulates the connection to reduce risk of accidental shorts while the inner conductive contact provides the required electrical conduction. Quantity: Pack of 50 provides spares for multiple devices, prototyping projects, or field service kits. How it works (simple explanation) The inner conductive material spans the two pins when the cap is placed over them, allowing current to flow (ON). When the cap is removed, the pins are separated and the circuit is open (OFF). Practical applications / use scenarios 1. Motherboard and internal drive configuration: Change device modes or master/slave settings on older hard drives and interface cards that use jumper headers. 2. Prototyping and development: Quickly set or change jump options on development boards, evaluation boards, or custom PCBs during testing and debugging. 3. Repair and maintenance: Keep a supply on-hand to replace lost or damaged jumpers when servicing computers, embedded systems, or industrial control boards. Specifications summary Pin spacing: 2.54 mm / 0.1 inch Color: Black Material: Plastic outer body with conductive internal contact Quantity: 50 jumper caps Reliable, low-cost components for configuring and testing electronic hardware where standard 2.54 mm headers are used.