Top Smart 18"Extended to 11" to 18" across the same intelligent 9" x 9" lace front base, the Top Smart 18" proves that smart design scales beautifully with length. Extending 11" to 18" across the intelligent 9" x 9" lace front base, this topper proves smart design scales beautifully with length and dramatic transformation. The lace front remains completely undetectable even at extended length, while the single monofilament blends seamlessly with your natural hair