Fits Almost Anything That Runs! “This set is a absolute necessity for using your compression tester on modern engines. There was the part I needed to adapt my compression tester for the 5.4 V-8 engine. Long spark plugs, deep holes.” - Dan K. Why Get Our Compression Tester Spark Plug Adapters Set? ✅One Kit for Many Engines: Compression testing becomes a hassle when your adapter doesn’t match the engine’s spark plug size. With four adapter sizes, this set fits most small to mid-size gas engines. Whether you're working on a motorcycle or a mower, you'll have the thread you need. All adapters connect to testers with a 14mm x 1.25 male thread, making it easy to use with most standard compression tools. ✅Covers Specialty Sizes Too: Includes the less common 16mm x 1.5 adapter for select Ford engines, giving you access to harder-to-match setups. ✅Engineered to Last: Durable construction and tight-sealing O-rings let you test reliably without worrying about leaks, wear, or inconsistent results. 📓FREQUENTLY ASKED QUESTIONS Q: What engines will these adapters work with? A: This set works with a wide range of gas engines, including motorcycles, snowmobiles, ATVs, lawn equipment, outboards, and small vehicles. It includes four common thread sizes to cover most spark plug ports. Q: Will these adapters fit my compression tester? A: These adapters are compatible with testers that accept a 14mm x 1.25 male thread. If your tester uses that standard size, the set will fit without any issue. ⚙️ Specifications: Color: Gold Item Weight: 0.25 lbs. Material: Steel and Rubber Compatibility: Compatible with testers using a 14mm x 1.25 male thread. Works with a wide range of gas engines including motorcycles, ATVs, outboards, lawnmowers, and snowmobiles. Designed to fit our compression tester W80579 and others with a 14mm x 1.25 male thread, providing compatibility with a range of testers. Product Dimensions: 6 x 3 x 0.7 inches 📦Package Inclusion: 1 x 10mm x 1.0 adapter 1 x 12mm x 1.25 adapter 1 x 18mm x 1.5 adapter 1 x 16mm x 1.5 Ford adapter