Semiconductor high frequency test probes are usually called double-ended spring probes. Common tip styles include B, J, J1, U and U1. The probes are extremely thin and miniature. However, the requirement for their test accuracy is very strict. They are mainly used for semiconductor tests and frequency tests of communication devices, for example, cellphones, walkie-talkies, computers, loudspeakers, etc. The smallest barrel is 0.15 mm in diameter.