This? http://www.aliexpress.com/item/BIG-B...641636472.html
"SB" is often found on older (newer one had trademark since abbreviation didn't protected by law ) 斯貝 (http://china-spey.com/ ) barrel
"RIK" http://www.riken.com.cn/en/about.asp or "DY" http://www.dongya.cn/prodlist.asp?page=7&tp=4&keywords= rings