Walmart offers the Duck Brand Extra Large Gap Weatherstrip Seal 3-Pack for $4.08. Opt for in-store pickup to dodge the $5.99 shipping fee. That's $1.36 per pack and the lowest price we could find by $9. (We saw it for a slightly cheaper per-unit price three weeks ago.) Each self-adhesive foam strip measures 3/4" x 1/2" x 10'.