This 4 In. wide 3/8 In. nap roller cover is designed for use in smaller spaces where a 9 In. roller cover won't fit but painting with a brush would take too long. The knit roller cover is thermo-bonded to the core ensuring low lint and the 4 In. width fits perfectly in bathrooms and kitchens or in larger rooms between windows or crown molding. You'll love the flexibility and smooth finish this smaller roller size provides. Designed for 4 In. frame Model No. 3455C.