Medical devices and methods for making and using medical devices are disclosed. An example system for delivering an implantable medical device includes a handle member including a seal assembly, wherein the seal assembly includes a turnbuckle assembly including a stationary member and a cap coupled to the stationary member. Further, the stationary member is coupled to an inner member and the cap is coupled to an exoskeleton disposed along an outer surface of the inner member. Additionally, the cap is designed to shift relative to the stationary member such that the exoskeleton is put in compression.