This is probably the last true friction only shifter produced by Suntour that had the Superbe Pro labeling.  It is actually a part of the Power Command shifter series in that it has a ratcheted assist to the friction shifting.  Unlike many of the other Suntour Power shifter this one actually is quite small in size and could easily be mistaken for a pure friction style device.  The markings on the levers are filled engravings.

The SL-SB00-B as shown is designed for a Braze-On downtube mounting.  However, the last picture shows a set I have converted over to Clamp-On.  My Clamp-On version uses a modified Huret clamp (from eBay) and parts from two other Suntour shifters to allow it to operate well in the ratcheting mode.

 Suntour did make a Clamp-On version called the SL-SB00-C, but none of the catalogs that I have seen show a picture of that version nor have I come across one yet.  I have tried several Suntour clamps from other shifters and none worked well with these levers!