Apollo 633/634 Replaced by 635/636
The Nice Apollo control boards 633/634 have been replaced by the 635/636 control boards. Upgrading to the next board can be slightly confusing if you don't remember which one you purchased. Looking at the board it may be confusing as well since it will say 633/634 on it as in the below picture. This is due to using the same base board. The model number you don't have is covered up to save cost to make sure you get the absolute lowest price. The answer to know which one you have is simple, it all depends if you have a single or dual swing gate opener. If you have a single you have the 633 and need to upgrade to the 635, if you have a dual you have the 634 and need to upgrade to the 636.