The 18-inch Zero Clearance Liner is an essential component for custom outdoor kitchen setups, specifically designed to accommodate Napoleon's BIB18PB (Power Burner), BIB18IR (Dual Infrared Drop-In), and BIB18RT (Dual Range Burner). Its purpose is to provide a safe barrier between combustible building materials and the burners, allowing for greater flexibility in installation without the risk of combustion or heat damage. This liner enables you to integrate drop-in burners seamlessly into your outdoor kitchen design, ensuring both safety and functionality. For proper installation, please refer to the instruction manual provided.