Check the listing for details. 2PCS Inline Spark Plug Testers, Small Armature Diagnostic Detector Tool for Car. Condition: New. Listed at 7.99 USD. Descriptions: Quick and Easy Test Helps Check the Condition of the Ignition System at each cylinder Connects Between Spark Plug & Spark Plug Wire Tests for no Spark Condition Essential for Trouble Shooting all Ignition Systems Problems Saves Valuable Time Quantity: 2 Benefits: Universal fit for all 2- or 4-stroke, single or multi-cylinder gasoline engines Immediately identifies a problem with spark or fuel Takes about 30 seconds Essential for trouble shooting all internal combustion engines Replaceable bulb Rust-resistant Tester snaps on tightly so it will not fall off when engine starts Great troubleshooting aid Durably designed for a long service life Saves time and money while also offering a safe secure way to identify spark No more guessing about the spark of the engine - It takes all the guess work out of knowing if you’re getting power to your spark plug No more shocks from holding a wire to the block DIY Tool Approved!