Tamper resistant receptacle, unlike traditional receptacles, offer the added protection of a permanently installed, spring-loaded slider mechanism capable of resisting insertion of single pronged elements s (such as keys, hairpins, or nails) while still allowing access to electrical plugs. Lutron Tamper Resistant Receptacles are compliant with article 406.11 of the 2008 National Electric Code (NEC®). The NEC prohibits the dimming of standard receptacles. The dimmable outlets of the Dual Dimming Tamper Resistant (DDTR) is specifically designed to mechanicaly reject all NEMA standard plugs and thus can not be used for any other device (fan, heater, vacuum, radio, etc.). These receptacles will only accept the special mating Lutron replacement plug for dimming use (RP-FDU). The result is an NEC compliant way to control a portable lamp with a dimmer.