Chronotrek‘s product is a wristband which allows the wearer to travel back in time. The decision of destination and time has to be made beforehand, since the product is only charged with the amount of energy neccessary for a specific journey.
However, in order to prevent timetravellers from changing the past, these trips take place in parallel universes which are basically identical to our universe.
You cannot use the wristband to travel into the future.
