Brand: LSE Lighting - Professional Ultraviolet Lighting Bulb Type: Germicidal Ultraviolet UV (254nm); Base Type: T5 4pin Base; Length: 12' This replacement UV Lamp by (LSE Lighting) brand is 100% compatible to use with Air Knight PX5 which requires 12' UV Lamp. All UV lamps listed are compatible brand (LSE Lighting) UV products. We do not sell Air Knight brand lamps. All Air Knight brand names, trademarks and logos are property of Air Knight respectfully. Warning: Ultraviolet Germicidal UVC light is harmful and dangerous to your eyes and skin. Please Use safety gear during installation.