Ordered this for my Slim Fast shakes and it does the trick wonderfully.
It comes in three parts. The clear base, which has easy to read embossed markings in millilitres, a clear plastic grid which fits inside to stir up the contents when you shake it and a blue top, with a permanently attached cap.
Pour your liquid in, add the powder, pop on the grid, screw the lid on and shake (I hope you closed the cap, otherwise it is now all over the kitchen, LOL)
Makes a great shake and it can be used for those powdered puddings/blancmange and dream topping if you feel naughty.
Just takes a rinse under the tap to clean, done in seconds, if you want a more thorough wash, pop in a teeny bit of washing up liquid and shake with water.