Abstract: the present invention provides a one way adjustable locking device for tensioning and securing a flexible line. The device has a cavity in it which has a bottom and or top tapered on an angle. This creates a cavity with the height on one end smaller that the other. A pin or ball is then assembled and retained into the cavity. The pin or ball travels up and down the cavity which is on an angle. The strapping, rope, or twine is threaded into the device above or underneath the pin or ball. The interference fit between the line and the pin or ball against the top or bottom of the cavity moves the pin or ball up or down the angled cavity depending on the direction the line is pulled. The design of the device enables the line to be adjusted and tensioned when pulled in the direction of the largest opening in the cavity.