Revision L MAC™ 3500 Resting ECG Analysis System 6-272021337-036Parts Lists: Field Replaceable Units (FRUs)MAC 3500 Top Cover Kit, pn 2030899-001Table 16. MAC 3500 Top Cover Kit, pn 2030899-001Item Item Description Qty1a 11 Items 1a and 1b comprise a single assembly.PLASTIC TOP COVER 11b * KYBD UNIVERSAL MAC3500 12 PLATE TOP COVER MAC3500 13 STANDOFF PLASTIC SNAP 81a1b23