Replacement Parts: This set includes 10 opticals ceramic cores sleeves and 10 metal head tips for fiber optics visual fault locators, providing safe replacements for maintenance needs Materials: Made from ceramic cores and metal components, these parts are sturdy and resistant to breakage, ensuring long in fiber optics testing Troubleshooting Tip: The red light fails to enter the fiber, inspect the ceramic cores for damage before considering a full fault locator replacement, saving time and cost Gentle Handling Required: The delicate ceramic cores require careful installation; avoid excessive force to damage and ensures optimal functionality Easy Installation: Simply open the cap, insert the component into the pen body, and tighten the metal head clockwise—no complex tools required for quick and hassle frees replacement, Manufacturer: Kaeltsyn