In the past few years, we have covered plenty of interesting arm and upper body trainers here. These Spin Strong rotary trainers are also wroth a look. Thanks to complete freedom of movement and air resistance, you will be able to target the right muscle groups with these.
The Spin Strong trainers work like a jump rope but you don’t have to worry about tripping over. You can go beyond upper body training by doing squats and lunges. 9 fun exercises are possible with this (e.g. figure eight, jump rope arms, one hand overhead, propellers, …).