This is a brand new reinforced cam chain manufactured by DID in Japan.
Model is
SD CAM CHAIN -DID25SD DHA
82L lengh for most of Honda minibikes and Cub type with 50 and 70cc engines.
Easy to install on genuine and upgraded vehicles.
Please check compatibility using part number.
Here are several technical informations from manufacturer:

DESCRIPTION
SPECIAL SOLID BUSH & DIE HARD αTREATMENT IS ADOPTED FOR HIGH PERFORMANCE ENGINE UNDER SEVERE CIRCUMSTANCE.
THINNER PIN O.D. REDUCES FRICTION LOSS.

REMARKS
※REQUIRED LINK NUMBERS DIFFER ACCORDING TO ENGINE TYPE.

APPLICATION
●THE FOLLOWING KITACO BIG BORE KIT ARE SUITED
LIGHT/STD/ULTRA 75-117cc FOR MONKEY
DOHC88cc FOR MONKEY
●THE FOLLOWING STOCK ENGINE ARE SUITED
MONKEY/SUPER CUB/XR50R/CRF50 SERIES 50-70cc
CB50/APE50 SERIES
GS50/BIRDIE50
APPLICATION
●THE FOLLOWING KITACO BIG BORE KIT ARE SUITED
LIGHT/STD/ULTRA 75-117cc FOR MONKEY
DOHC88cc FOR MONKEY
●THE FOLLOWING STOCK ENGINE ARE SUITED
MONKEY/SUPER CUB/XR50R/CRF50 SERIES 50-70cc
CB50/APE50 SERIES
GS50/BIRDIE50