Commercial Specification Grade Straight Blade Plugs and Connectors are rugged performers. They are moisture, chemical and abuse-resistant. And they're ideal for indoor and outdoor use. All of these features and benefits are common to 15 A and 20 A Commercial Specification Grade Plugs and Connectors. TPE rubber-backed plugs and connectors stand up to rough use and protect against dirt and moisture. Deep-slotted, backed-out terminal screws draw backwire clamps securely over stripped leads for maximum conductivity.