Stylus Writer by Vernet Magic (GV$3)

Comes with a $3 gift voucher on your next purchase :) 
 
(Gimmick and Online Instructions)
 
You can generate a prediction inside a completely sealed envelope!
 
Includes 1 gimmicked envelope, 5 white cards and 1 Stylus Writer and video download with full explanations
The spectator can hold the envelope
The envelope is in full view
Predict any word or number
No window envelope
No forces or switches
Comes with everything you need to perform straight out of the box