Test Probe Tips are used to connect test equipment to the circuit/chip/design being tested. Often the device consists of a cylindrical rod with?a head that is concave, convex, a?crown, a clamp, a point or blade, or a hooked end.? The other end is usually?a wire lead. The characteristics are tip type, connection type, tip length, overall length, voltage rating, and cable rating (CAT I, CAT II, CAT III, CAT IV, IEC).