29B129 Belt connector (used for splicing the 41a3589 series belts) [K029B0129]

It would be helpful if the website had a note that both part numbers 29B129 and 29B130 should be ordered together to make a complete part for shortening a belt. After 10 days of trying to figure out why none of the belts I had been looking at were the right length I discovered that my belt length (and opener rail) had been customized to compensate for the beam that crossed my garage. It was frustrating to then order/receive the belt and part 29B129 only to find out that I had to go back to order part 29B130 to get my job finished.