The stl10507683 irwin strait line chalk line kit comprises a chalk line and 113g blue chalk the irwin chalk line has a heavy duty case which is constructed of durable aluminum alloy it has a steel plated hook and large grip anchor ring which provide better holding power its retractable self locking metal handle allows reel to be used as a plumb bob its twisted cotton line holds more chalk for multiple line strikes holds approximately 55g of chalk line length 30m