Complete Replacement Set: Includes 4 full knob and bolt sets, offering a reliable backup for seasonal maintenance or unexpected repairs. Durable Construction: Made from high-strength plastic and zinc-plated steel to resist rust and withstand outdoor use over time. Tool-Free Assembly: Designed for quick hand-tightening—no spanners or special tools required, saving time during installation. Size Reminder: Bolt diameter is 8mm; please check compatibility with your mower before ordering to ensure a proper fit. Multi-Purpose Use: Ideal for general garden equipment, not limited to lawnmowers—also suitable for other outdoor machinery with similar fittings.