If you buy Blackmail, you WILL need replacements. So I recommend getting a few sets to get started and get you ready to preform in front of people. The device lasts a while, but you will be thanking yourself when you buy extras.
this is the SHIZNITZ of mentalism, so practicle, it is just like having a swami with you anytime, enywhere.
straight forward and direct.
great tool :)