--- product_id: 3334226 title: "Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12)" brand: "permatex" price: "¥41087" currency: JPY in_stock: true reviews_count: 8 category: "Permatex" url: https://www.desertcart.jp/products/3334226-permatex-81878-12pk-ultra-copper-maximum-temperature-rtv-silicone-gasket store_origin: JP region: Japan --- # Temp range -75°F to 700°F 8x flexibility vs cut gaskets 3x oil resistance vs standard silicones Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) **Brand:** permatex **Price:** ¥41087 **Availability:** ✅ In Stock ## Summary > 🔥 Seal the deal with ultra copper power – your engine’s new best friend! ## Quick Answers - **What is this?** Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) by permatex - **How much does it cost?** ¥41087 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/3334226-permatex-81878-12pk-ultra-copper-maximum-temperature-rtv-silicone-gasket) ## Best For - permatex enthusiasts ## Why This Product - Trusted permatex brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Bulk Pack Value:** 12 tubes of premium copper gasket maker—stock up, save, and never worry about leaks again. - • **Flexibility That Lasts:** Eight times more flexible than traditional gaskets, adapting perfectly to your engine’s every move. - • **Sensor-Safe & Low Odor:** Engineered for modern tech—non-corrosive and safe around sensitive sensors with minimal smell. - • **Oil-Resistant Powerhouse:** Triple the oil resistance means no leaks, no mess—just pure performance. - • **Unmatched Heat Endurance:** Handles extreme temps from freezing cold to blazing 700°F without breaking a sweat. ## Overview Permatex Ultra Copper RTV Silicone Gasket Maker is a professional-grade, high-temperature sealant designed for automotive applications. It offers superior adhesion, sensor-safe formulation, and exceptional resistance to oil and vibration. With a temperature tolerance from -75°F to 700°F intermittent, it’s ideal for exhaust manifolds, valve covers, and other critical engine components. Sold in a convenient 12-pack, it delivers long-lasting, flexible sealing performance trusted by mechanics and enthusiasts alike. ## Description Permatex Ultra Copper Maximum Temperature RTV Silicone Gasket Maker is the most advanced, high temp RTV silicone gasket available. Three times more oil resistant than conventional silicones and eight times more flexible than cut gaskets, it is sensor-safe, low odor, and non-corrosive with superior adhesion. Highest operating temperatures for 4-cylinder, turbocharged or high-performance engines and OEM specified, with a temperature range of -75 degrees fahrenheit to 700 degrees fahrenheit intermittent. Also resists auto and shop fluids and vibration. These gasket makers offer significant performance advantages, excellent torque retention and hi-temp, sensor-safe properties. Extended warranties, engine sensors and new component materials such as aluminum, bi-metal alloys and high-tech plastics, have created the need for superior RTV silicone gasket makers in both OEM production and service applications. Permatex always has the right gasket maker for your application. Review: Works great on headers! - Since I have been using ultra copper I have had zero header leaks! I've used it on valve covers and intake end gaskets with no issues with oil leaks, just good all around. I buy in bulk to save money, I just keep it in my house where the temps are controlled and it last for around two years no problem maybe longer? Review: Actual product - Great price for a name brand product. Will buy again if available. ## Features - Most advanced, high temp RTV silicone gasket available - Three times more oil resistant than conventional silicones; eight times more flexible than cut gaskets - Sensor-safe, low odor, and non-corrosive with superior adhesion - Temperature range -75F to 700F intermittent - Suggested Applications: Exhaust manifolds/headers, valve covers, oil pans, timing covers, water pumps, thermostat housings ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B001REZA1W | | Best Sellers Rank | #1,477 in Automotive ( See Top 100 in Automotive ) #4 in Gasket Sealers | | Brand | Permatex | | Brand Name | Permatex | | Color | Copper | | Customer Reviews | 4.8 out of 5 stars 29 Reviews | | Global Trade Identification Number | 30686226818783 | | Included Components | Tube of Gasket Maker | | Item Form | Paste | | Item Weight | 2.9 pounds | | Manufacturer | Permatex | | Material Type | copper | | Model | 81878-12PK | | Number of Items | 12 | | Part Number | 81878-12PK | | Surface Recommendation | Miscellaneous | | Unit Count | 36 Fluid Ounces | | Water Resistance Level | Waterproof | ## Product Details - **Brand:** Permatex - **Color:** Copper - **Item Form:** Paste - **Item Weight:** 2.9 pounds - **Surface Recommendation:** Miscellaneous ## Images ![Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) - Image 1](https://m.media-amazon.com/images/I/81PxU8Ql4PL.jpg) ![Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) - Image 2](https://m.media-amazon.com/images/I/81u1kGuxI+L.jpg) ![Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) - Image 3](https://m.media-amazon.com/images/I/61leGRet8qL.jpg) ![Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) - Image 4](https://m.media-amazon.com/images/I/71eou1YAKvL.jpg) ## Available Options This product comes in different **Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works great on headers! *by M***0 on July 6, 2023* Since I have been using ultra copper I have had zero header leaks! I've used it on valve covers and intake end gaskets with no issues with oil leaks, just good all around. I buy in bulk to save money, I just keep it in my house where the temps are controlled and it last for around two years no problem maybe longer? ### ⭐⭐⭐⭐⭐ Actual product *by R***N on January 26, 2019* Great price for a name brand product. Will buy again if available. ### ⭐⭐⭐⭐ High temp, but not recommended for oil and gas *by G***T on March 31, 2025* Used it on a few things. So far so good. Unfortunately I did not read that it's NOT good for oil and gas products. The main reason I got it was to seal an intake leak on old cast iron head. ## Frequently Bought Together - Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12) - Permatex 82180-12PK Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker, 3 oz. Tube (Pack of 12) - Permatex 82194-12PK Ultra Grey Rigid High-Torque RTV Silicone Gasket Maker, 3 Ounce (Pack of 12) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/3334226-permatex-81878-12pk-ultra-copper-maximum-temperature-rtv-silicone-gasket](https://www.desertcart.jp/products/3334226-permatex-81878-12pk-ultra-copper-maximum-temperature-rtv-silicone-gasket) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-09-20*