An attachment device attachable to a string, rope, cord or other flexible line that remains in a fixed position on the line without knotting the line or clamping the device to the line. The attachment device is quickly attached and removed without the need for additional tools to attach or release the device from the line. The device includes a secondary attachment to allow a second device to be permanently attached to the attachment device, allowing the second device to be quickly attached and released from a line.