The E289 Series from Citel are surge suppressors. When plugged into a Citel base, these suppressors have been crafted expressly to protect sensitive telephone, datacom, and instrumentation equipment against harmful lightning surges and electrical transients. These suppressors utilize a hybrid that combines a fast response time (website. The NEBS/Telecom Forum on InterferenceTechnology.com fields questions and comments on every aspect of the rapidly changing telecom industry. Whether you’re looking for testing services, the right component, or the applicable standard, just post your query to the Forum and look for an answer from one of our many knowledgeable readers.