Wheelock Series E60 Ceiling Speakers are designed for high efficiency sound output, with dual voltage (25/70 VRMS) capability and field selectable taps from 1/8 to 2 watts. Optional Extender (E60 Ext) is for mounting to 4" backboxes with no extension ring.The Series E60 Speaker Strobe models incorporate the Low Current draw Series RSS Strobes. These ceiling mount round models are available in Wheelock patented MCC multi-candela ceiling strobe with field selectable intensities of 15/30/75/95cd or the high intensity MCCH strobe with field selectable 115/177cd.Series E60 Speakers and Speaker Strobes provide high audio output with clear audibility and are designed to meet the critical needs of the life safety industry for effective emergency voice communications, tone signaling and visible signaling to alert the hearing impaired.The low profile design incorporates a speaker mounting plate for faster and easier installation. Each model has a built-in level adjustment feature and snap-on cover with no visible mounting screws.