OEM REPLACEMENT: High-quality A/C receiver filter drier designed to replace Trans/Air 212021 and is compatible with Carrier 14-00288-00 and ACT 97027301 systems. INTEGRATED SIGHT GLASS: Features a top-mount moisture indicator and sight glass for real-time refrigerant diagnostics and easy maintenance checks during HVAC service. PRECISION FITTINGS: Equipped with 1/2-inch Male Insert O-Ring (MIO) inlet and outlet connections for a leak-free, secure fit in commercial shuttle bus air conditioning lines. MAXIMUM PROTECTION: Contains XH9 desiccant to effectively absorb moisture and prevent acid formation, protecting compressors compatible for Starcraft, Champion, and ElDorado buses. DURABLE CONSTRUCTION: Built to withstand the high-duty cycles of transit vehicles; dimensions are 2.5" diameter by 8.25" total length. Optimize your fleet's cooling performance with the Trans/Air 212021 Filter Drier. This essential HVAC component serves as the primary line of defense for your bus air conditioning system, trapping moisture, debris, and contaminants before they can cause catastrophic compressor failure.