I used this product to run speaker wires through an interior wall down into the basement. This tool worked perfectly and made the job very quick and easy. It was an economical solution to a challenging problem. I ran the wires through the cold air return with minimal disturbance (3/8" holes on each end). The magnet is small enough to fit through small holes just big enough to get the twisted pair speaker wire through. The flexible extention is easy to bend as needed to retrive the chain. Very simple product that works well.
You can toss out your metal fish tapes if you get this product. This is much easier and way faster. You have to straighten out the coiled retriever wand and I question how many times you can bend it before it breaks. It's also a bit pricey, but it got the job done quickly so I feel it was worth it.