Allen Avionics makes precision custom-built LC noise filters including band pass filters (400 Hz to 500 MHz), high pass filters (100Hz to 1000MHz), low pass filters (50Hz to 5000MHz; 20, 200, 500, and 1000 watts), and diplexers, with applications including microwave filtering.

Capcon International makes several EMI noise filters, including low pass filters and miniature sized component filters as well as microwave absorbers and other absorbative filters. Their minuature models filter either AC or DC power lines for up to 10 Amps at 50VDCW, 100VDCW, or 115VACW. Capcon also offers military grade filters.

Corcom Products makes EMI/RFI filters including LC filters, Power Line filters, ISM filters, Signal Line filters, Power Entry modules, DC filters and facility filters. Their power entry modules have a current rating of 1 to 15 Amps, while their DC filters have a current rating of 1 to 125 Amps. Corcom filters can be used for microwave filtering as well as medical and military applications.

Cosel makes component sized Din rail mountable AC and DC (±50 VDC) noise filters with a rated current from 1 to 30 amps, single phase (250 V) and three phase models (500V).

Filtronetics makes custom EMI/RFI noise filters such as bandpass, high pass, bandstop, and lowpass filters, with frequencies of >1MHz to 6GHz. They also have LC filters, diplexers, surface mount models, and ISM filters. Some applications include military and microwave filtering.

LCR Electronics designs and manufactures EMI/RFI filters such as power entry filters, power line filters, signal line filters,  and facility filters. Their power entry filters have a max rated voltage of 250VAC with a rated current of 1-20A (filters) and 1-10A (modules) and an operating frequency of 50 or 60Hz. Applications include industrial three phase controllers, medical grade filters, microwave filtering, military spec filters, and appliances.

Microwave Filter Company makes noise filters and components including LC filters, band-pass filters, miniature filters, ISM filters, and Diplexers. Their high quality passive filters operate on 5 Hz to 50 GHz frequencies and their WiMax diplexers use bands which are mutually isolated by a minimum of 55 dB with a maximum 1dB of insertion loss per band.

MtronPTI makes custom noise filters including LC filters, with a frequency range from 0.000 to 5000.000 MHz, available as surface mount, through-hole or connectorized with an Input/Output Signal to 200-Watt and higher. Also available are microwave filters and mil-spec filters, with certification for MIL-STD-790, MIL-PRF-3098, and MIL-PRF-55310.

PA&E makes ceramic EMI/RFI filters for use in electronic packaging including microwave high-frequency packages, a flexible leaded filter with a rated voltage from 50 - 500VDC and a rated current of 5 Amperes, and broadband low-pass filters with insertion-loss of 20, 40, or 60dB/decade with voltage ratings from 50 VDC to 240 VAC and current ratings of .10Amp to 50Amp. Applications include microwave filtering, medical grade, and military specifications.

Tusonic makes a wide line of EMI/RFI filters including both AC and DC line models, surface-mount filters, feed-through filters, and custom filters. Other EMC products carried include ceramic variable trimmer capacitors, and radial leaded disc, tubular, and WEECON Plate capacitors.