This article covers all Sony PRO 1GB (MSX-1GS) and 2GB (MSX-2GS), PRO DUO 1GB (MSX-M1GS), 2GB (MSX-M2GS) and 4GB (MSX-M4GS), Hi-Speed PRO DUO 1GB (MSX-M1GN), 2GB (MSX-M2GN) and 4GB (MSX-M4GN) models. Clue #1 Front view 1. Genuine uses print ready/control vector art technique to print all the letterings. Fake uses inferior hi-res bitmap to copy the genuine, so zoom in a bit to see the printing flaw. The font on the fake usually is bolder, messy, out of focus and rub off easily. 2. Genuine card is often thinner than fake. Try fitting the card into an adapter and you may find that it has problem as it doesn't seems to fit into the adapter easily (feels like its squeezing in). Newer 2GB fake (1959MB version) even has problem fitting into a PSP (PlayStation Portable). Clue #2 Back view 1. The font face, font size and printing technique are the main criteria to differentiate the genuine from the fake, so you must take notice. 2. Genuine has wider 'MADE IN JAPAN' than 'ICES/NMB-003.' while fake usually is the other way around, and some are missing a critical dot '.' at the end of the '-003' word. 3. Genuine has the letter 'S' in 'MSX-2GS' as Italic than the 'S' used in 'COMPLIES CANADA' and 'ICES/NMB-003' wordings. Fake is using identical normal font face throughout! Also note that genuine has a shorter stroke of the '/' character whereas fake has longer stroke and it is taller than any other characters. 4. Beware of known FAKE 2GB cards circulating eBay with incorrect model number 'S.MSX-2GN' and serial number 'L406L1L .' The extra S. at the front was covered with a sticker with the rest looks very close to a genuine card. 5. On the 10 gold metal stripes/contact, genuine is covered fully by the black plastic housing from the top to the bottom end. Fakes may have small black holes on the some metal stripes, some have its gold metal stripe not fully covered by the black plastic housing. Some fakes have internal green color PCB board exposed as pictured displaying its inferior manufacturing defect. 6.Genuine uses print ready/control vector art technique and has all letterings engraved by laser-etched into the plastic shell of the card. Fake uses inferior hi-res bitmap to copy the genuine, so zoom in a bit to see the printing flaw. The font on the fake usually is messy, out of focus and rub off easily. To know if it is printed, just use your finger to feel the surface as the letterings are a bit raised. Clue #3 Retail Packaging view 1. Genuine clear plastic packaging has long (staple shape) heat seals indicated by the yellow arrows. Fake has round dot glue seals (not heat) indicated by the red arrows. 2. Genuine hi-speed card (with red-stripe) has 3 vertical staple heat seals on each side of the pack. Genuine also has additional 2 horizontal staple seals across the top of the packaging not found on the fake. This applies to both 1GB/2GB/4GB retail packaging product. 3. Genuine normal-speed card (without red-stripe) has 9 vertical staple heat seals on each side of the pack while fake only has 3 dot seals on each side. Genuine also has additional 6 horizontal staple seals across the top of the packaging not found on the fake. This applies to both 1GB/2GB/4GB retail packaging product. 4. To the right hand side of the packaging there are 4 pictures. Some fake has the 4 pictures arranged in incorrect order. 5. Check holographic sticker status in Clue #5below Clue #4 Capacity and Transfer Speed 1. Genuine 2GB has a capacity of 1909MB while some devices will read them at 1910MB. Some older fake 2GB shows 1948MB and 1959MB of memory space when being tested. Newer fake 2GB may now show any of these figures including the 1910MB of a genuine. However some 2GB fakes only have a true capacity of only 512MB/1GB. Try transferring as much data as possible to your card and see if it will hold close to 2GB as most fake 2GB won't hold anything near 2GB. 2. Genuine hi-speed card (with red-stripe) has a transfer speed at about 80Mbps. Fake has a slower transfer speed with 1948MB fake actually can do about 65Mbps to 70Mbps and 1959MB fake atmost 60Mbps. Clue #5 Hologram 3D Golden Sticker 1. If item comes in retail packaging, it will have a golden metallic 3D 'SONY holographic sticker' at the front of the retail box, as pictured. Newer fakes now also have similar identical holographic sticker. Bring the packaging to your nearest SONY retail outlet and ask for a SONY Anti-counterfeit Handy Viewer to tell if your item is genuine. The viewer has 2 see through Lens. 2. Genuine hologram will appear as complete BLACK when see through the Left lens and Normal on the Right lens. 3. Counterfeit hologram will appear as Normal through both Left and Right lens. clue #6 (tip from gameunreal) when checking on your psp if the card has magicgate support, if it appears as UNKNOWN then it's fake. information from ebay.