This is the latest consignment of socks human rights campaigners in South Korea are hoping will reach people in the impoverished north by balloon.
Activists from South Korea and other countries including the UK, Canada and Austria are sending 1, 000 pairs.
They come complete with a similar number of leaflets urging a North Korean uprising.
North Korean defector Lee Joo-seong says socks are a valuable black market commodity.
SOUNDBITE: LEE JOO-SEONG, NORTH KOREAN DEFECTOR SAYING (Korean):
"We're sending these socks to help North Korean children because the socks can be traded for food and money if they reach the impoverished North Korean people."
U.S. activist Andrew Post says involvement in the balloon launch is very rewarding.
SOUNDBITE: ANDREW POST, U.S. HUMAN RIGHTS ACTIVIST, SAYING (English):
"The best part of it is knowing that the other end there is people waiting for these supplies, that they can really use them, and the knowledge that you might very well be saving human lives in the end of the bargain so it's an awesome opportunity."
In the past North Korea has threatened to retaliate against such balloon launches.
This launch comes as tensions run higher than usual following Pyongyang's announcement of plans for a rocket launch in April.
Paul Chapman, Reuters
