Snuggly fitting silicone rubber boot. Protects Thermapen Mk4 from drops to concrete or hard surfaces. Provides protection from radiant heat. Fits Zipper Wallet, Leather Wallet and wall bracket. Use only for Thermapen Mk4. Does not fit older models. The silicone boot is translucent. Silicone is not clear nor transparent and so when the protective boot is installed the color of your Thermapen Mk4 will seem muted.