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 30 countries! By combining two hemispherical sound amplification chambers with carefully designed sound channels, it achieves natural energy free amplification of between 10 and 20 decibels. This means an increase of 2 to 4 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.
Free USPS Priority Mail shipping within the US!
Our American Black Walnut is another highly prized hardwood known for it’s rich brown colors and pale tan steaks of sapwood which are common throughout the tree. Colors can range from light cream to deep espresso, often within the same small piece of wood. Walnut finishes very well and has a lustrous feel. It is our most popular wood specie.