In a bottom valve apparatus of a hydraulic shock absorber in which a flow passage is formed in a bottom piece, and a check valve opening and closing the flow passage and a spring urging the check valve are fixed to one face side of the bottom piece by a fixing member, such as a nut, the check valve and the spring are subassembled in the fixing member, such as the nut. The extended dielectric lens can be implemented with a feed antenna to improve the directivity of the antenna. The finely matching step employs control point matching between the first original image and the second original image using small image patches at a scale of the one of the first original image and the second original image having lower resolution. Corresponding sample conduits of the portable pressure transducer removably couple with the pressure ports. The nozzle may then slide over the guide surface to the stop.