【Premium Quality Electrical Adapter】This light socket outlet 3-prong is sturdy enough for working with electrical, household, Industrial, machinery and other appliances.【Wall Outlet Converter】The 2 prong to 3 prong outlet adapter can covert a grounded electric extension power cord to an AC outlet without a grounding pin slot, perfect for older houses or offices with AC wall outlets that can not accept grounded plugs.【Polarized Plug】The 3-prong to 2-prong grounding adapters is polarized and better than the un-polarized plug adapters, because polarized plugs only allow you insert the plug into the outlet slots in one direction, wide blade to wide slot, narrow blade to narrow slot, which ensures neutral-to-neutral, hot-to-hot and provides a measure of safety for the appliances and house wiring to be aligned in terms of polarity. This also explains why most household appliances’ plugs are polarized.【Portable and Easy to Use】It's small and compact so you can take a 2- to 3-prong adapter in your briefcase or laptop bag anywhere. Just plug the adapter to a wall socket and you will have a 3-prong outlet. This 3 prong to 2 prong adapter is also portable for travelling to Japan. All outlets in Japan is 2-prong, so with this adapter, you can easily charge your 3-prong electronic devices.【Grounded Protection】This three-prong to two-prong adapter plug fits snugly into the wall outlet without falling out even when plugging a heavy cord into the adapter. It has a metal grounding tab / terminal to fit neatly under the outlet plate screw and provide a proper grounding for safety. Note: Using a 2-prong to 3-prong outlet adapter on ungrounded 2-prong outlets is not recommended.