The Original Koostik is the result of a year of product evolutionary design and refinement. It is our first passive solid wood acoustic amplifier for iPhone, and this now iconic design is in daily use in over 45 countries! By combining two hemispherical sound amplification chambers with carefully designed sound channels, it achieves natural energy free amplification of between 10 and 25 decibels. This means an increase of 2 to 5 times the volume! Please note that due to it's unique design, the Original does not allow for the connection of your charger while in use with your iPhone. It is a totally "unplugged" amplifier!
The Original Koostik is compatible with all versions of the iPhone, but be sure to select your specific iPhone above in order to get the correct fit.