SPC Electronic Indicators AC Adapter Works with the following SPI Electronic Indicators... 21-001-3 21-002-1 21-003-9 21-004-7 21-005-4 21-006-2 21-007-0 21-008-8 21-009-6 21-010-4 21-011-2 21-012-0 21-013-8 21-014-6 21-021-1 21-022-9 21-023-7 21-024-5 21-025-2 21-026-0 21-027-8 21-028-6 21-029-4 21-030-2 21-031-0 21-032-8 21-033-6 21-034-4