This Electronic Handheld Bug Zapper drops from $7.99 to $2.99 to $2.79 with code 81993934 at Harbor Freight. This is the lowest price we found for any electronic insect zapper, with similar ones going for around $20. It's designed to kill flies and other small insects and can be used indoors or outside. Better yet, it has 4.3 out of 5 stars by 87 reviewers. Shipping is a flat $6.99, so it's a great deal when you buy multiples. Sales tax is charged in most states.