Dear P'Lek,
I think there is a problem with search in Product Info when using '-' (dash), I have a plan to rewrite whole product info after integrate all new designs to eliminate these problems.
For the time being, please access it direct by use this URL: http://www.optimus.co.th/cms/headmain/mproduct/edit?ModelNo=RK-901-1025-XX00
(You can change the ModelNo (red) part by put the model you want there (or copy from the frontend and paste is okay too))
http://www.optimus.co.th/cms/headmain/mproduct/edit?ModelNo=RK-901-1025-XX00
e.g. Model: RK-901-1150-XX00 URL is http://www.optimus.co.th/cms/headmain/mproduct/edit?ModelNo=RK-901-1150-XX00
Please let's me know if you have any trouble access it krub.
Best Regards,