Unique helpful item every sound man should have on hand! 70v in, line level XLR and RCA out Connect to a 70v speaker line and get line level (or mic level) out! Adjustable level (recessed screw driver adjustment) can set output range 0 - 1.5v to feed a mic or line input Some applications: ADDITIONAL PAGING AREAS -You have a retail or factory paging system and need to add more speakers in another area of building or without overloading the existing amp : simply connect this to existing speaker line and connect this units output to another amplifier with speakers. MOH (music on hold) feed your phone system music on hold input from the nearest background music speaker. RECORDING. you want to record audio from a factory or church PA system that does not have a dedicated recording output: Simply connect this to the 70v output of amp or anywhere along the speaker line and connect this units output to a recording device. MIXING EMERGENCY PAGING with house event sound. Connect this units input to existing paging speaker line and connect this units output to your live show mixer. SCHOOL PA. to connect a dedicated Stage, pool or Gym system to the office Intercom all call paging etc. Connect this unit to the speaker line on the intercom wall speaker (25v or 70v) in the room and connect this units output to the dedicated room sound system XLR or RCA input. BACKGROUND MUSIC INTERFACE many retail, restaurants etc have 70 speakers for music, you can tap this onto a speaker line to feed another area amplifier, powered speakers, etc. or perhaps feed into a portable outdoor sound system for seasonal outdoor dining events. CCTV AUDIO recording, if you have a security DVR with audio input and want to record your store or factory announcements along with a video feed, this could help with that. (hear what they say announce about the boss while he is out!) 2 WAY RADIO interface, feed your 70v speaker paging announcements into a 2 way radio system (you may need to also add a voice activate relay to activate radio PTT if not transmitting continual) Fairground paging - feed 70v ground page/ emergency page announcements into your show stage system xlr input so all can hear! Ground loop issues- input and output are isolated via internal transformer (can solve some hum issues if your amplifiers standard aux out/line out is causing ground loops connected to external equipment) 8 ohm use, yes, you can use on 8 ohm amplifier outputs, rather than 70v but will need sufficient level to drive it enough. If you have a 100w or greater amplifier and a good level coming out of it, and you turn up the adjustment level on this unit, you should be OK. Note There are also some internal jumpers you can cut/solder to experiment with to change its level if you still need more gain. Can use as portable device or mount on wall via built in key way holes on back size 6.2"x3.5"x2.4"