This is a very exiting bayonet; an atractive design if it was for real, but it is a completly fantasy product.
Manufactured in China with the typically low quality.
No need to into details, it is a mix of the Dansih M1915 (see
LINK) and the French M1874 for the Gras rifle.
The marking on the back of the blade is completely jibberish :-)