Left & Right Rear Suspension Strut Kit for MDX 2007–2013 and ZDX 2010–2013. Compatible with MDX (2007–2013) and ZDX (2010–2013). Application: MDX, ZDX Year Range: MDX 2007–2013; ZDX 2010–2013 OE/Part Number: 37309 Interchange Numbers: 37309, 51606STXA03, 349025, 51605STXA55, 51605STXA05, 52610STXA53, 51605STXA03, 51606STXA05, 51605STXA58, 51606STXA55, 51605STXA56, 51606STXA58, 51606STXA56, 52610STXA02, 52610STXA04, 52610STXA54, G64080 The strut assembly uses damping oil tested for viscosity, density, and low-temperature performance to maintain function across a temperature range of –40°C to 80°C. Strut tube wall thickness and spring weight conform to dimensions. The spring meets fatigue requirements with testing exceeding 600, 000 cycles. Installation dimensions match specifications.Extension and compression travel are consistent with the factory rear strut assembly. Dampers are tested for 3 million cycles with no oil leakage observed; damping force attenuation does not exceed 20%. Welded mounting brackets are tested under 0.8 MPa tensile pressure for 400, 000 cycles. Rubber dust cap is tested for through 300, 000 cycles without failure. Rubber mounting components are designed to dampen vibration transmitted through the suspension system. Materials and manufacturing processes follow quality control checkpoints to support consistent build integrity. Packaging materials comply with environmental standards.