MIL-DTL-7627G, DETAIL SPECIFICATION: INDICATOR, TURN AND SLIP, 28V DC (24 AUG 2010) [SUPERSEDING MIL-I-7627F]., This specification covers 28V DC, hermetically sealed turn and slip indicators. The indicators are of the following types, as specified (see 6.2).MS28041-1 - 4 Minute Turn, Dark Ball, Fluorescent Dial MarkingMS28041-1A - 4 Minute Turn, White Ball, Lusterless White Dial MarkingMS28041-1B - 4 Minute Turn, Dark Ball, Lusterless White Dial MarkingMS28041-1C - 4 Minute Turn, Dark Ball, Fluorescent Dial MarkingMS28041-1D - 4 Minute Turn, Dark Ball, Lusterless White Dial MarkingMS28041-2 - 2 Minute Turn, Dark Ball, Lusterless White Dial MarkingMS28041-2A - 2 Minute Turn, White Ball, Fluorescent Dial Marking