Manufactured in Japan, the new OLO™ marker is developed using patented technology that features a free-flow ink system. Each OLO half-marker contains 2ml of ink, for a total of 4ml in an OLO double-ended marker. Traditional markers only have approximately 2ml of ink total. OLO’s patented free-flow ink technology utilizes over 90% of the ink compared to standard marker technology, with only 65-70% ink usage.