Product review (5 stars): Works well.
This unit is pretty lightweight and fairly quiet given what it does - spins really fast to pull out water from your clothes.
There is no on/off switch.  When plugged in, the unit will fire up when the lid is shut.  When you move the latch to open the lid, the motor will shut off.

Sometimes, when trying to spin up with heavy wet clothes, the unit might not be balanced enough to spin up and the inner tub will bounce around.  I re-adjust the clothes, put the plastic cover over the clothes, push down and close the lid....  off the races the Spin Dryer goes.

I let it run until I don't see any significant moisture coming out of the drain (maybe 5 minutes).  The non-cotton clothes seem close to dry and the cotton clothes are just a bit damp.  I hang dry the clothes or put them in the dryer on the shortest time setting.

IMO, this kind of device is essential if you hand wash your clothes or use a portable machine without any kind of good spin cycle.
I use this machine with the Basecamp Portable Washing Machine as a backup system to our full size washer/dryer.