Check the listing for details. Chamberlain Liftmaster Circuit Board 41AC050-4 Purple Learn Button. Condition: Used. Listed at 49.50 USD. Chamberlain Liftmaster Circuit Board 41AC050-4 Purple Learn Button There are a lot of interchanges for this listing that have similar part numbers but the last letter will be different. This is simply a year designation and they are all identical boards. You may receive one of the following interchanges, but they are guaranteed to work on your unit if you have one of these numbers.... 41AC050-4A41AC050-4B41AC050-4C41AC050-4D41AC050-4E41AC050-4F41AC050-4G41AC050-4H41AC050-4I41AC050-4J41AC050-4K41AC050-4L41AC050-4M Compatible with many garage door openers with a purple learn button and purple antenna (315MHz operators)... PART# 41AC050-4 NOTE: The part you receive WILL NOT be the exact one pictured, however it will be the same part number OR AN INTERCHANGE listed above, in similar condition. Items are used and may have paint, nicks, scratches, missing stickers, fading etc, but they are GUARANTEED to work or your MONEY BACK! - 60 Day Free Returns!- Ships Fast!- Ships Free!