This pack includes two KYB shock absorbers for the rear axle. They are gas pressure, twin-tube, telescopic shock absorbers with top and bottom pin mounting types. The Excel-G series is designed for optimal performance. Cross references: BILSTEIN: 19-135021, 19-135052, 19-136592, 19-136622, 19-144221, 19-144238, 19-145266, 19-145297, 19-152769, 19-152790 BOGE: 32-K67-A, 32-L41-A MONROE: E2068 SACHS: 310984, 311409 Compatible with the following OEM references: BMW: 31316767321, 31316768211, 31316768219, 31316771177, 33504035261, 33504035872, 33526768917, 33526768921, 33526771555, 33526771559