These Dia-Compe brake levers are maybe not the most high end, but they are still kind a cool.
I do not know how well they work but I have heard people complaining about them, because they are a bit smaller than typical Shimano parts of the same time. IIRC they where originally BMX parts?
The most striking difference from Shimano Deore XT brake levers are the smaller size of the Dia-Compe Advantage 5 levers, they are also a lot less advanced. No return spring, no SLR, just a lever.
SL stands for Super Light and if you look closely there are holes in the body of the brake lever. I do not remember how light these levers are but they should be almost half as light as XT Brake levers which where tanks in comparison.
A bit scratched and in used condition, these are worth 15 euro. SOLD