It is mechanical scale ,The material of surface:PVC,not absolutely round ,it is a little elliptical The specification of this kind of round mechanical scale is as following:The shape:it is not absolutely round ,it is a little elliptical.The material of surface:PVCThe material of body:metalCapacity - 120 kg. (Minimum)Graduation- 1kg.Size- 300mm x 255 x 55mm .Net Weight:1.4kg. mechanical scale