Pilates soft ball.
This is the ultimate Pilates prop in my opinion!
You can use it for delicious release exercises for the neck and low back to effectively release tight structures. The beauty of using the ball for this is that you are totally in control of how your body moves and s can tailor the exercise to best fit you.
It can also be used as a really challenging prop to target those deep stability muscles.
It’s cheap and small ( it can be easily deflated) which is another bonus.
If I am ever going away this is one prop that I always take with me !