The Rattler-C was my first CNC-based head shape that had a three plane sole, flat bumpers and shoulders that are parallel to the top line of the putter. It is a popular shape that has been a great-performing head.
My Rattler-C's are machined using 1018 Cold Rolled Steel and can be done in a good number of finishes, noted on the Spec Sheet, linked below.
From time to time, I have examples of this putter built and ready for shipping, with a 1-2 day lead time. Reach out to me at firstname.lastname@example.org anytime and I can update you on what is currently pre-built.
Download 2020 Spec Sheet Here