DOGYU Outer Wall Inspection Tool Pen-Type Percussion Stick G Pen [Storage-Up To 140-620mm] 01129Product code: 01129 Total weight: about 60g Ball diameter: 17mm Storage longest: about 140 620mm Shaft: 7 stage telescopic stainless steel tube pen clip type scale JAN code: 4962819011294 Less repulsion using brass balls! Since the balls are brass balls, there is no iron rust. Can be used for shooting with a scale of 10cm increments. To check the position of 9 hole square holes and 6 square holes. For checking the length of digital camera photography