1Replacing OEM number for reference: 17138616418, replacement for X3 X4 F25 F26. 2Engine coolant recovery tank, used to store excess pressure and coolant as the radiator heats up. 3The reservoir helps to keep the radiator full at all times and makes the radiator more efficient. 4Original standard, direct replacement for the old or broken coolant expansion tank. 5Can be installed easily and quickly, does not require complicated operations and tools. Item Type: Engine Coolant Reservoir Material: ABS OEM: 17138616418, 17137823544, 17137639464, 17 13 8 616 418, 17 13 7 823 544, 17 13 7 639 464 Fitment: 04.14 - 08.17 Replacement for X3 (F25) sDrive 20 i 10.11 - 08.17 Replacement for X3 (F25) 20 i 04.12 - 08.17 Replacement for X3 (F25) 28 i 01.11 - 10.12 Replacement for X3 (F25) 28 i 09.10 - 08.17 Replacement for X3 (F25) 35 i 10.12 - 03.14 Replacement for X3 (F25) 18 d 04.14 - 08.17 Replacement for X3 (F25) 18 d 09.10 - 03.14 Replacement for X3 (F25) 20 d 04.14 - 08.17 Replacement for X3 (F25) 20 d 04.11 - 08.17 Replacement for X3 (F25) 30 d 06.11 - 08.17 Replacement for X3 (F25) 30 d 04.11 - 05.16 Replacement for X3 (F25) 30 d 10.11 - 08.17 Replacement for X3 (F25) 35 d 04.14 - 03.18 Replacement for X4 (F26) 20 i 04.14 - 03.18 Replacement for X4 (F26) 28 i 04.14 - 03.18 Replacement for X4 (F26) 35 i 12.15 - 03.18 Replacement for X4 (F26) M 40 i 04.14 - 03.18 Replacement for X4 (F26) 20 d 04.14 - 03.18 Replacement for X4 (F26) 30 d 04.15 - 03.18 Replacement for X4 (F26) 30 d 04.14 - 03.18 Replacement for X4 (F26) 35 d 1 x Engine Coolant ReservoirPlease double check the part number of your item, matching information is for reference only. If you are unsure of the item, please contact us before buying to avoid unnecessary return, thanks