Home / Control Panels / Accessories / Option Cards / Simplex 566-221 Simplex 566-221 $236.34 Board Expansion 4100U/ES Availability: Please Call for Lead Time Simplex 566-221 quantity Add to cart Request a Quote This product is already on your Quote Request Browse your Quote Request Factory NewBrand: Simplex FireAlarm.com Part #: 72534 Categories: Accessories, Control Panels, Option Cards Manufacturer Part #: 566-221 Specifications Resources Information Weight 1.00 lbs Brand Simplex Condition New Resources4100U Service Parts List Simplex – Data Sheet