Since we are living in a money dominated society, good products and services are copied, even - in some countries - with government's consent! Just to swipe some extra money. Many manufacturers - of whatever product and/or service - all over the world are fighting permanently against illegal copies of their products. Breweries, fashion houses, cosmetica manufacturers, musicians, filmmakers and many more are searching the global market for illegal copies every day. Also Nikon Corporation has to face counterfeits, that are copies of existing Nikon products. Some products - offered by pirate producers - Nikon does not even produce, although the article is sold in an 'official' Nikon box (see below) !!
Nikon never produced an AC-adapter EH-55 !!
Nikon Corporation is warning for these fake products on various web sites. Nikon USA, Nikon UK other Nikon representations are listing fake products they have found. It is clear that Nikon never will give any guarantee if a genuine Nikon product is damaged by the use of a counterfeit.
Known Nikon articles like remote releases, batteries, chargers and net adapters (aka AC-adapters) are offered on internet and on various camera fairs.
During the 1980's many camera manufacturers introduced cameras with a built-in zoom lens + flash + winder, like Olympus did with its AZ-300. A terrible plastic copy - indicated as made in Japan, but actually made in China - was marketed as Nikon F41 !!
There is also a gray market/circuit on which products are offered, almost identical to the original Nikon product, but often not as good and not as safe. Using these copies may harm/damage your Nikon camera, flash light, lens, etc.
Above the original (grey) Nikon SC-17 flash cable and a (black) copy, marketed as 'no-name' SC-28a. Nikon offers a SC-28 but never used the SC-28a code.
The SC-28a cable looks nice but may give short-circuit problems in your camera because of the metal flash shoe.
Above a fake Nikon EN-4 battery for the Nikon D1-series! The outside sticker promises more capacity than the standard Nikon EN-4 (2000mAh), although - looking inside - the capacity is nearly the same!
So be aware of fake Nikon products!!!!