Dry Battery Work Light,Emergency Outdoor Work Light Lamp ,Multi-Function Work Light,Worklight With Magnet In Camping NINGBO ZHENGUO INTELLINGENT LIGHTING CO.,LTD , https://www.zguolight.com In the maintenance, often encounter large diameter round and sample, can not be used with ordinary rules. To this end, we have made two tools for rounding large diameters. The utility model has the advantages of simple structure, easy manufacture, convenient use, wide application and the like, and solves the difficulty of drawing a large diameter circle in the work. Figure 1 shows the large diameter gauge. When using, first loosen the adjusting bolt 3, move the adjustment big 4 to adjust the required size, and tighten the bolt 3