KVA meters measure the apparent power of AC devices in kilovolt-amperes (KVA).

Signal filters block or decrease (attenuate) unwanted frequencies or signal wave characteristics.

Frequency discriminators are RF or microwave devices that are used to detect a signal with a particular frequency.

Network test equipment is used to test, probe, and analyze telecommunication, network and telephone systems.

Conductivity meters, dissolved solids meters, and resistivity meters are analytical instruments that measure the conductivity, dissolved solids, and/or resistivity of a liquid sample.

Communications and network software is used for the setup and management of digital communication networks such as LAN and WAN computer networks, electronic mail, FAX, audio and video networks, wireless communication systems, etc.

Audio transformers are involved in the transmission of voice or sound signals.