I believe it is a 14’. I purchased it used off of Kijiji (similar to Craigslist) for $40, so it’s the cheapest form of exercise I have at my disposal other than running!
I’ve probably only had it now for around 3 weeks so I have only around 10 jumping sessions on it, but I have gone out to jump on it when my knee or hips were feeling beat up and hopped off of it feeling much better. This could be just from forcing blood flow into the sore area which loosened it up, but regardless I’m enjoying it.
I do have a training log: