Product Function: This hollow cast plug is a specialized high-temperature resistant accessory designed for Skutt ceramic kilns. It seals the viewing port to minimize heat loss, stabilize kiln temperature, and conserve energy. It also allows flexible adjustment of kiln ventilation. After firing, removing the plug accelerates cooling while preventing flames, sparks, and dust from escaping the kiln. preventing external dust contamination of finished pieces. This accessory balances temperature control efficiency with operational convenience and product protection. Precision Dimensions for Reliable Seal: this hollow cast plug is approximately 3-1/2 inches long and tapers from 1-1/4 inches to 3/4 inches, these peephole hole plugs create a reliable heat resistant seal to minimize energy loss Compatibility: Compatibility: This peephole plug Designed for the viewing ports (fire viewing ports/observation ports) of Skutt brand electric/gas kilns.The kiln plug/spy hole plug compatible with almost all Skutt electric kilns: KM, KS, KT, GM series, etc. Fit KM series: KM818, KM1027, KM1227, KM1231, KM1241, KM1427, etc.FIT KS series: KS818, KS1027, KS1227, KS1231, KS1241, etc.FIT KT series: KT819, KT1027, KT1227, etc.Fit GM series: GM814, GM1017, GM1222, etc.Also fit all electric kilns with standard 1-inch (1 ") peephole. Premium Material: The kiln plugs are Constructed from lightweight, high-temperature-resistant ceramic. Withstands thermal shock and extreme kiln temperatures. Features a one-piece tapered structure for easy insertion/removal and a tight seal, ensuring long-lasting durability. Easy Installation: No need to observe kiln conditions during firing. Simply insert the plug into the kiln viewing port to seal for insulation or adjust ventilation. After firing, remove the plug to accelerate cooling. Wear heat-resistant gloves during high-temperature operations. Regularly inspect accessory condition and replace immediately if cracked or damaged. After-Sales Service: Thank you for choosing our product! Should you have any questions or suggestions during use, please feel free to contact us at any time. Our customer service team is always on standby to provide you with prompt and professional assistance.