Have a 522g that is loopable for sale. It's been sitting in my safe as a backup for a few years, but now I'm upgrading again and will make my current pump a backup. Never used it for looping, but think it would be awesome for somebody who did want to do it.
email or text with questions. side sticker is missing, other than that it's in really good condition. price includes shipping in the continental united states, can ship elsewhere for a little extra