This external speaker went with a Bell & Howell 1956 model #385 Projector. Its a 12" Part # 28035 and is marked 16 ohms 25 watts. It has 2 jack plug ins on back of speaker. It has about a 50-100 ft double ended cord that comes with it (see photo). I was going to test but the phono jack size is not the standard size we use today, its a bit smaller? (see photo). I took a picture of projector and the amp it was used with. I am selling the amp on one of my other auctions. One of the rivets was broken and replaced with a small bolt & screw see photo. Its sold As Is since my testing was stopped with the jack problem but its probally a good bet since the projector it came with tested well and the amp it was used with was not hugh. Buyer pays 26 lbs USPS parcel rate from 75763.