The Nitto UI-85EX is one of the few oversize 31.8mm clamp stems Nitto makes.  It is made of cold forged aluminum so it is super stiff and strong.  It is available in 5 lengths to suit almost any rider.  The stems are designed for 1 1/8" steerer tubes, but include a shim for using with a 1" steerer.

Lengths 70, 80, 90, 100, and 110mm
Bright Polish finish
31.8 mm clamp
+/- 8 degrees.