Ripstick

If you are looking for an inexpensive- it cost me $67- workout tool that will give you results in less than half an hour a day, Google this and check it out. I bought it out of curiousity after seeing a Facebook ad and it kicked my ass and I was in really good shape going in. I still do my workout with resistance bands- thanks Scrap- in the morning and do this after work and my results have more than doubled.
Next year, when I kick off my career as a 60 year old fitness model you will see me on the Sports Illustrated swimsuit issue cover. I will try to keep it modest.

Is this it?

//youtu.be/7xYPxXp8w_M

no, this is it.
https://youtube.com/shorts/GVfymlviEQg?si=vAnzDcvP_coQ_YlL

I prefer cardio, using cross trainer/bike, skipping and punch bag.

We’ve come a long way from those old metal spring resistance bands. Who hasn’t bloodied a lip at least once getting hit with the handles ;D. This looks very compact, wonder how the bands hold up? I’ve always been a free weights and kettle bell guy. But the last few years my back and right knee say “ohhh hell no you’re not” :p.

atrophy is real, this looks like it would be great for smaller muscle groups.

In my experience, you don’t want to overstay your welcome with a single band because they will stretch pretty fast. If you double them up you will be working with that for a minute, and you can buy new bands. Or go to Walmart and get some thick rubber bands.
I was doing 1000 push ups every other day and using dumbbells- iron, not to be confused with the dumbbells I work with- and my joints were killing me.
As far as the Ripstick, that was just the first video that came up. There are others that, in my opinion, are better but it probably comes down to what you are trying to accomplish. You are correct in saying that it would be great for smaller muscle groups. After a week I was very aware of particular muscles that I was not previously acquainted with.