Add to Cart Quick view Rockwell Collins 851S-1 Extender Boards A-4 & A-7 in Excellent Condition Rockwell Collins MSRP: Now: $99.99 Was: Rockwell Collins 851S-1 Extender Boards (2) A-4 & (1) A-7 They are in Excellent Condition. There are two A-4 Boards. One has the cables on the board the other does not. The A-7 Board is marked "encoder driver" A-7 MSRP: Now: $99.99 Was: Add to Cart Quick view Qty in Cart: 0 Quantity: Decrease Quantity: Increase Quantity: Price: MSRP: Now: $99.99 Was: Subtotal: Add to Cart