I've been shooting the Merlins for the past 4 -5 years now. One of the best customer service in the industry. I think the Tempest has been out of production for more then 3 years now. I still think you might be able to get modules for the rapid cam form Merlin though. The rapid cam was modified a few years ago but I think you have the original model(which will make a difference in the modules). They will know by the #on the cam. You will have to go to the Merlin site and find a dealer closest to you and I'm sure they can help you out. If you don't have a dearler close then contact Pinwheel archery. They are the Internet sales Rep. Also 300 Archery. I have dealt with Kevin numberous times and he is a pleasure to deal with. Good luck. Jerry