Where can I buy a natural gas detector?

You can purchase a natural gas detector pen through Amazon.com or at your local Home Depot. You can expect to pay around $50.

Most home improvement stores such as Home Depot carry natural gas detectors. Your best bet is to call any local home improvement and ask a representative.

You should be able to find this product at most major home improvement and hardware stores as it is relatively common. I purchased mine at Home Depot. Online, you can purchsae this sort of product from Amazon.com.