Honeywell 621-4550 Description Description Honeywell 24V DC Source Input Module Related products HONEYWELL AX51-051-001 HONEYWELL DM106-0-A-00-0-R-1-00000-000-E0 HONEYWELL 621-3560 HONEYWELL 620-3590 HONEYWELL 621-9990 HONEYWELL 621-6575