No idea about this stem. I've never seen one like it before, with the letter "S" enclosed. Could be Suntour, I guess - maybe! - but I'm only saying that because the stem shifters are Suntour and the brake levers are Dia-Compe... so no brainer, right? Well the dang thing is on a 70's (I think) era Follis. Right... French! Since when do French bikes sport Japanese components? Sure, somebody could've swapped some stuff out, but looks to me like they must've done it thirty years ago if they did. Can't find this example on Velo-Base either. Anyone ever seen it before? ID? Very curious.