It is intended to provide a means of easily removing a portion of blood bleeding from pierced skin, which has not been taken into a blood sensor but remained on the skin, in a blood test with the use of a blood test apparatus. The conductive diffusion region may provide a conductive oath from top of the substrate to bottom of the substrate. 05 to about 3 weigh percent and can include those additives conventionally used in polyolefin foam compositions, including antioxidants and stabilizers, processing aids, etc. Due to the mounting device of this invention, it is possible to improve work efficiency while mounting the coil assemblies of solenoid valves in the ECU’s housing, and so the production cost of the brake systems is reduced. The coarse section has a porosity greater than a porosity of the fine section.