(Upgraded SP02) ANCEL SP21 Spark Plug Tester, Dual Holes Test Spark Plug Tool, Car Motorcycle Engine Ignition Tester 0 to 6000RPM Spark Tester Socket with Mistake-Proof Design

【Must-Have Diagnostic Tool – Fix Hard Starts & Poor Performance】Slow starts, weak acceleration, or high fuel use? These could be signs of faulty spark plugs. ANCEL SP21 spark plug tester quickly checks spark plug firing quality to help you diagnose issues early and decide if replacement is needed—delivering faster, clearer results than traditional inline testers

【Dual-Port Design – Test Smarter, Replace Only What’s Needed】Why settle for one at a time? The dual-hole design lets you test and compare two spark plugs simultaneously. Instantly identify weak or failing plugs without guesswork. Save time, avoid replacing good plugs, and improve engine performance with smart, side-by-side diagnosis

【Simulates Real Engine Ignition – Adjustable Up to 6000 RPM】No complex setup—just insert the spark plug and turn the dial. ANCEL SP21 spark plug tester simulates actual ignition behavior and allows fine-tuned RPM adjustment (0–6000 RPM) for accurate performance checks. Tip: 2000 RPM is often sufficient for testing most spark behavior

【Test Safely with Clear Visibility】Built-in clear protective cover lets you safely monitor spark activity during testing. It shields you from accidental sparks while offering an unobstructed view of the spark intensity—ideal for both professionals and DIYers focused on safe and reliable diagnostics

【Works on Most 12V Gas Engines – Cars, Motorcycles & More】Compatible with all standard 12V gasoline engines and spark plugs with an insulator diameter less than 12.2 mm, a length not less than 33 mm, and not exceeding 43 mm. Perfect for cars, motorcycles, lawnmowers, ATVs, and small engines. Whether you're a weekend DIYer or a professional technician, this is a must-have tool in your diagnostic kit

⚠️ Note: This spark plug tester is not compatible with very short spark plugs. Due to the plug length, the contacts may not reach the bottom of the testing port. If you're unsure about compatibility, feel free to contact our support team at 📫toptool-service@outlook.com—we’re here to help