Variable Mu Retube Kit Version BThis kit is only for Manley Variable Mu's (and mastering versions) with the serial number falling between MSLC5265 MSLC94006, also includes MSLC6xxx or MSLC8xxx. Includes (2x) 5670 tubes for input, (2x) 5751 tubes for second buffer, (2x) 12AL5 tubes for rectifier, and (2x) 5687 or 7044 tubes for driver output. Please note the T bar modification for these units can only be applied to MSLC8xxx and MSLC9xxx serial numbers. Be aware that some tube brands