Longo Chalk Line - 30m This chalk line from longo can be used for lengths of up to 30 metres. The chalk line has a handle to help retract the chalk line quickly and easily when not in use, as well as a ring pull that can be used to hold the chalk line in place when in use, and is contained within a durable plastic casing to ensure the chalk line is kept untangled and neat. A chalk line is used for a wide range of applications, but is primarily used to mark a straight line between two points, which can be used as a guide when cutting, installing or laying materials.