1. Physical Dimensions (Primary Difference): XLC-60-12-MAS: Length = 176.0 mm XLC-60-12-MA: Length = 136.0 mm The MA variant is 40 mm (approximately 23%) shorter, representing the most substantial distinction. This reduced length typically indicates an optimized or iterated internal layout and thermal design, likely employing more compact magnetic components or an adjusted PCB layout to fit applications with stricter spatial requirements. The longer body of the MAS part may offer marginally better thermal headroom. 2. Price: XLC-60-12-MAS: $46.90 XLC-60-12-MA: $51.17 The more compact MA part carries a price premium of approximately 8.3%. This reflects its potentially updated design, higher component integration, or the increased design and manufacturing costs associated with achieving a smaller form factor. For cost-sensitive projects with ample installation space, the MAS part holds a clear advantage. Summary: The choice between the MA and MAS depends on project priorities. If space constraints are paramount, the smaller MA part should be selected, accepting its higher cost. If cost control is more critical and the installation space permits, the MAS part represents the more economical and performance-equivalent option. Both share identical electrical specifications and are direct drop-in replacements.