Krystaller, Krystalfiltre ect.

Advanced Crystal Technology  

Eska Crystals

G & G Communications - Komplet liste over krystaller etc.

Geyer Electronic

HEC Inc. - Krystaller, oscilatorer etc.

International Crystal Manufacturing Co.

International Radio - Crystal Filters

Quartzlab Marketing Inc.

Sentry Manufacturing Company - Krystaller

S.P.K. Electronic Ltd.