Denso Heater Core DRR12101 Replaces 42553964. A heater core is installed in both climate controlled and heater-only vehicles, to provide heat to the cabin. High temperature engine coolant provides heat when the cabin fan control is switched on from the dashboard.Alternatively please use the cross reference table above. It remains the responsibility of you (the customer) to check the specification of this component and carefully compare to your original before ordering/installing. This product has no reviews yet, however see what our buyers say about our other products.. DIY Car Service Parts has now added a dedicated sales and distribution team to handle customers questions and pre-sales enquires, we are experts in our field so if you have a query let us know! Unit 2 King Street Trading Estate Middlewich Cheshire CW10 9LF. This item is in the category "Vehicle Parts & Accessories\Car Parts & Accessories\Starters, Alternators, ECUs & Wiring\Other Starters, Alternators, ECUs & Wiring". The seller is "diycarserviceparts" and is located in this country: GB. This item can be shipped worldwide.