Never used, all parts are tested and quality checked before shipping. Replacement Part Numbers: Briggs & Stratton: 590588, 591139, 593961; For Briggs & Stratton engines: 08P502, 093J02, 09P602, 09P702; Stens: 150 012, 150012; Stens 150 012, 150012; 0 0-012; ratio 003-522. Compatibility and purpose: - Designed as a reliable replacement starter for Briggs & Stratton and Stens engines listed above. - Fits models that require a pull back style starter with matching mounting pattern. Mounting specifications: - Mounting hole diameter: 5.5 mm (0.22 in) - Mounting hole distance: 172 mm (6.8 in) Function and operation: - Pull back starter: easy to use with a pull rope to start the grass cutter. - Built for quick installation and dependable starts. Use scenarios: - Scenario 1: Replacing a worn or faulty starter on Briggs & Stratton engines that match the listed part numbers to restore lawn equipment performance. - Scenario 2: Keeping as a spare in workshops or service carts for Stens 150 012 / 150012 models to minimize downtime. - Scenario 3: Maintenance stocking for equipment with 5.5 mm mounting holes and 172 mm mounting spacing, ensuring ready replacement during peak season.