The idea of a transparent force bag was first devised by U.F. Grant many years ago, but he somehow wrongly called it "Transparent Change Bag".
This idea was a breakthrough for stage mentalism, and later on Jeff Busby and Gene Nielsen created a Zip-Loc-like model.
This one is also a Zip-Loc-like model, but it has three compartments instead of two. This means that you can force several different objects (if you need). The red line will help you to know which side you are using.
If you want to use two compartments only, just close the Zipper of one bag, and that's it, now you have a regular double force bag.
Dimensions Approximately: 23 x 32 cm. English instruction with ideas included.