This heater blower motor resistor is designed as a direct replacement for OEM part numbers 8K0820521B and 8K0820521C.It is compatible with select A4 B8 (2007–2016), A5 (2007–2017), Q5 (2008–2017), A8L D4 (2009–2018), S4, S5, S8, RS5, and SQ5 models.The unit features a metal and plastic construction and is engineered to regulate blower motor speed for consistent HVAC performance.Includes: 1 x Heater Blower Motor Resistor.Compatible models include: - A4 Allroad B8 (8KH) 2.0 TFSI (04/2009–05/2016) - A4 B8 (8K2) 1.8 TFSI, 2.0 TFSI, 3.2 FSI, S4 variants (2007–2015) - A4 B8 Avant (8K5) 2.0 TFSI, 2.7 TDI variants (2008–2015) - A5 (8T3) Coupe 1.8 TFSI, 2.0 TFSI, 3.2 FSI (2007–2017) - A5 Convertible (8F7) 1.8 TFSI, 2.0 TFSI, 3.2 FSI, S5, RS5 (2009–2017) - A5 Sportback (8TA) 2.0 TFSI, 3.2 FSI, S5 (2009–2017) - A8L D4 (4H2, 4H8, 4HC, 4HL) 2.0 FSI, 2.0 TFSI Hybrid, 2.5 FSI, 3.0 TFSI/TSI, 4.0 TFSI/TSI, 4.2 FSI/TDI, 6.3 W12, S8 (2009–2018) - Q5 (8RB) 2.0 TFSI, 2.0 TFSI Hybrid, 3.0 TDI, 3.0 TFSI, 3.2 FSI, SQ5 TFSI (2008–2017)