Above is the 1999 8v issue to celebrate the China'99 Stamp Expo.
This particular sheetlet is available from a Holland dealer at a very low price. The bottom left corner stamp is torn off, on the gum side there is a red ink handstamp "MUSTER" which is the German word for specimen.
This specimen sheetlet is neither from COPREFIL nor Cambodian Post, it is the work of Global Philatelie GmbH, the philatelic agent of Cambodia. The Pirmasens based company served as the sole marketing agent of Cambodia and other COPREFIL client nations in the second half of 1990s.
Philatelic agencies sometimes send specimens to wholesalers, dealers and individual collectors to attract philatelic orders. In Asia Mongolia is very well known for her handstamped on gum specimens, Cambodia is way less heard of.
Interested collectors are advised not to spend much on these specimens as they have very low philatelic value.