Variable Mu Retube Kit Version CThis kit is only for Manley Variable Mu's (and mastering versions) with the serial number MSLC94007 and up. Includes (2x) 5670 tubes for input, (2x) 5751 tubes for second buffer, (2x) 12AL5 tubes for rectifier, and (2x) 12BH7 tubes for driver output. Also note that if you want the T bar modification for this unit, it can only be applied to MSLC8xxx and MSLC9xxx serial numbers. Be aware that some tube brands are subject to change over time and may not