Our enclosed type FPM controls use different boards than the chassis type FPM controls. The boards are very similar and have identical functional abilities, but the boards within the enclosures have some physical characteristics that are not on the chassis control. There are replacement boards available for the standard enclosed type FPM controls. The part numbers are as follows: Models 81X (X = 5,6,8) – part no. 43100451 Models 83X (X = 5,6,8) – part no. 43100483 Models 85X (X = 5,6,8) – part no. 43100485 Contact an authorized distributor to purchase these replacement boards. A distributor locator is available online at http://www.bodine-electric.com/Asp/Distribuloc.asp.