Over time, the factory plastic coolant expansion tanks that Honda/Acura includes from the factory can weaken and fail from heat and pressure cycles. The PRL Coolant Expansion Tank kit replaces the factory tank with a more robust aluminum version. Our 6061 aluminum tank will not be affected by temperature and can hold higher pressures so that it will outlast the factory tank. Our reservoir also more than doubles the tank's coolant capacity to 1.32 quarts (1.25 liters), while the stock tank only holds .58 quarts (.55 liters), allowing for a greater volume of coolant to carry heat away from the engine internals while maintaining a tidy engine bay. Our tank is constructed from 3mm thick aluminum and features internal baffling to prevent coolant sloshing and cavitation. The kit includes all necessary fittings to fit either the FK8/FL5/DE5 Civic Type-R/Integra Type-S applications, as well as the fittings needed to fit the 2016-2021 Civic with the 1.5t engines.