[. . . ] 3 The receive signal can be switched from `TONE' to `PULSE'. 2 Insert the headset plug into the jack on the side of the T50 telephone. Important: After installing your T50 telephone, it is necessary to wait for10 seconds prior to use. [. . . ] The telephone company may make changes in its facilities, equipment, operation or procedures that could affect the operation of the equipment. If this happens, the telephone company should pro- Vide you advance notice in order for you to make the necessary modifications to maintain uninterrupted services. If you experience problems with your headset, please refer to the warranty section for information on warranty and repair service. If the problem is causing harm to the telephone network, the telephone company may request that you remove the equipment until the problem is resolved. In extreme cases, the telephone company may be forced to disconnect your service before notifying you of the problem. Caution: Users should not attempt to make such connections themselves, but should contact the appropriate electric inspection authority, or electrician, as appropriate. Terminal device provides an indication of themaximum number of terminals al lowed to be connected to a telephone interface. The termination on an inter face may consist of any combination of devices subject only to the requirement that sum of the Ringer Equivalence Num bers of all devices does not exceed 5. The following 90-day warranty and service information applies only to the original owner of this product purchased and used in the U. During this warranty time, if the product is defective in workmanship or materials, Plantronics at our option will replace or exchange it for a model of equal value. Damage caused by improper care, accidents, unauthorized repair or modifications are not covered under this warranty. Neither Plantronics nor your retail dealer or selling distributor has any responsibility for any incidental or consequential damages including without limitation, commercial loss or profit, or for any expenses, loss of time, or inconvenience. Some states do not allow exclusion or limitation of incidental or consequential damage, so the above limitation or exclusion may not apply to you. To obtain warranty service, please prepay shipment and return the unit to the appropriate facility listed below: Please use the original container, or pack the unit(s) in a carton with sufficient pack ing material to prevent damage. Name and telephone number of person to call, should contact be necessary. Damage occurring during shipment is deemed the responsibility of the carrier, and claims should be made directly with the carrier. [. . . ] When using your telephone equipment these basic safety precautions should be followed to reduce the risk of fire, electric shock, and injury to persons. This product gets its power from the telephone line after its 10 second initiation time so it is important to know that it can spark if the cord is damaged. Do not use this telephone to report a gas leak in the vicinity of a gas leak. [. . . ]