These aren't shifters, they're shifter holders. You can barely see them behind and under the shifters there. That's what you get. Just the mounts is all you get, no shifters.
They hold Shimano 8s or 9s bar-end shifters so you can still shift and index with Shimano thumbshifters. It's a clever idea, a smart idea, a thoughtful one, and the world's a better place for these. Paul used to make an adapter to make these work with Silver shifters but have since discontinued it. These won't work with Silver shifters.
The MTB model fits Albatross, Dove, mountain bike bars (like our Nitto bullmoose) any bar with a 22.2mm grip diameter. On ROAD bike dropbars this is the thicker section of the bar where the stem clamps on which for all our Nitto dropbars is 26.0mm diameter. ROAD 26.0mm thumbies have been discontinued by Paul, sorry.
NOW sold individually, just in case you want to jump on the "one-by" bandwagon. Please specify Right or Left side.