Able to accommodate a wide range of differential line spacings on PCBs, the P80318 and P80318X 18-GHz TDR hand probes greatly improve differential TDR measurement integrity for electrical serial data signals. Each probe can resolve small spatial features used to determine the differential impedance and if differential lines are matched in length. Probe pitch is continuously adjustable from 0.5 mm to 4.2 mm (signal to signal). The P8018 and P80318X are functionally identical, but the P80318X comes with a second probe body. Base price: $3990. Tektronix, www.tek.com .