---Twin aluminium core will achieve up to 30% greater cooling capability than OEM ---Black coating designed to optimise heat dissipation, resulting in consistent lower temps ---Keeps engine temperatures down, ideal for track use ---More water volume within a channel means greater cooling efficiency ---Designed to be a direct replacement for ease of fitment Fitment ---Vauxhall / Opel Astra G MK4 2.0 turbo Z20LET 1999-2005 models (incl. GSI and SRI) ---Vauxhall / Opel Zafira MK1 2.0 turbo Z20LET 1999-2005 models (incl. GSI and SRI).