Product review (5 stars): Toasty warm!
This device works great. Our laundry room was always quite chilly in the winter, what with the dryer vent letting in cold air, and it's on the north side of the house to boot. With the Heat Keeper, no more. This thing delivers as promised. It feels great when you're doing laundry in the winter now. Unlike some of the other comments, I think it provides just the right amount of humidity also, especially in the driest days of winter. (That may depend on where you live, though.) Furthermore, installation was a breeze. In fact, the one end fit right into the outside vent tightly; no clamp even necessary. For the end attached to the flexible vent pipe from the dryer, I just used the metal squeeze clamp I was already using, and so didn't bother with the plastic clamps included. Well worth the low price I paid.