his microfiber bonnet is designed to fit on a small triangular steamer head. Made to decrease the aggressiveness of the bristles and decrease the intensity of the steam. Increasing cleaning ability with the power of microfiber. Designed for McCulloch A275-001 Triangle Head (works with MC1275 Canister Steam Cleaner), or similar size/shape brush heads 4"x4"x4" 75/25 Blend Twist Pile Microfiber