Shimano Xtr Deore M9120 Zee Saint Sintered W/Spring
With copper plated backing plate and sintered front for extreme conditions like down hill, suitable for the same range as D640. Tektro G-Spec

Shimano Zee BR-M640
Shimano Saint BR-M810/ M820 Shimano Deore XT BR-M8020

MT420/520 M9120 M7120