How we evaluate products

We compare published specifications, name the source of each number, and do not claim to have tested anything ourselves.

What we do

• Collect specifications from the manufacturer's own datasheet or product page.
• Record the source link and the date we checked it.
• Calculate comparison figures, such as price per watt-hour, from those specifications.
• Mark any figure we could not verify as "to be verified" instead of guessing.

What we do not do

• We do not claim hands-on testing. We have not run these products.
• We do not promise that a product will protect your home or your health. Follow the manufacturer's instructions and local safety guidance.
• We do not use fear to sell products.

Safety items

For carbon monoxide detectors, heaters, generators, and water filters, we rely on manufacturer documentation and official sources such as the CPSC, EPA, and CDC, and we link to them. Generators and fuel-burning heaters must never be used indoors or in a garage.

Prices

Prices change often. We show current prices only through Amazon's official tools, so the price you see on Amazon is the one that applies.