SPECTRE MAF SENSOR ADAPTER/TUNING KIT, ALUMINUM, POLISHED -- 3 in. O.D.; 4 in. height; Includes 2.25 in., 2.5 in., and 2.75 in. calibration tubes, five adapters, and installation hardware; Made of polished aluminum body with ABS components; Calibrated to a specific diameter tube; Allows you to add 3 in. modular intake system while maintaining the correct diameter at the sensor to retain calibration; Designed for vehicles with drop-in style mass air flow sensors.