Can I add THC to my machine later? June 21, 2021 21:50 Updated You do not need to include THC in your initial purchase, it can always be added to your machine later on. Related articles What is the difference between Torch Height Control (THC) and Initial Height Sensing (IHS)? Can I use THC on the original CrossFire machine? THC Function - Internal Wiring XL Kit Lower Rails Differentiation How can I place an order?