Yes, for the CL220, you drill 2 3/8" holes and clamp the 'nipples' onto them. As I said, the install is easy. I would love to give you one of my typical 'long winded' responses as to how to do it, but my dog had surgery today (she's fine ) and I need to 'comfort' her some and go to bed

I'll be back tomorrow if you want some more specifics on installing one