PB 3318324 45" 8 Double Row Proex/Wire Main Sweeping Broom for Power Boss 72 Series Sweepers. A blend of 3 different diameter polypropylene filaments and crinkle wire. Our most popular broom in this series. Polypropylene proex filaments can be used indoor or outdoor and in wet or damp condtions, making it a very versatile material. Not designed for extreme heat. Mixed with a small amount of crinkle wire for attacking packed or stubborn debris. Fits Minuteman Power Boss 72 Series Sweepers, including SW/72 and SW/72 Deluxe. Replaces Minuteman Power Boss 3318324, 318324.