110PCS Silicone Rubber Tapered Plug, Coldairsoap High-Temperature Resistant Rubber Stoppers 8 Size 1/16" to 5/8" for Hole Plugs, Spraying, Coating, Painting Protection. High-Temperature Resistance: Our silicone rubber plug for coating with high-temperature resistance of up to 200℃-300℃, has strong stability and corrosion resistance.
eBay