Tired of sanding dowels, round stock, profiles and corners? I hope that with this Thing your life will be easier.
Those are just simple sanding pads/blocks. Wrap some sanding paper around and start sanding.
There are three types in different dimensions: for round stock(inner and outer) and for corners.
Design Spark Mechanical source file attached, so you can easily modify the pads yourself.
If you don't want to print it yourself, you can buy a set here(affiliate link - you pay nothing extra, I get some change):
You can watch how I've printed it and tested here:
Print it upright. You can add a brim for better adhesion. Use 3 perimeters.
It could be better if printed with some rubber like material.