26″, 32h, £63

NoTubes say:

The ZTR Crest Rim – Wider and stiffer than the Alpine, lighter than the Arch, the ZTR Crest is built for cross country and light trail use. Next generation BST provides the tire stability and tubeless seal. Wins at the Tour Divide and BC Bike Race have established the Crest 29er as the leader in light, reliable big wheels.

Features
Disc Only
Weight 340g
Tape Width 21-25mm
New updated graphics for 2012!

DCR says:

The crest is the rim that everyone thinks they want. It gives you such a light weight that you would think you are running carbon fibre. It isn’t that flexy because it is still a very wide rim. However there are a number of reasons why you should probably consider the Arch as an alternative. The Arch is much stronger, much stiffer and importantly can tolerate 125kgf rather than a mere 95kgf. Because you can run such higher tensions, the wheel will be significantly stiffer and strong as well as more stable and spokes are less prone to breaking. You could probably, as a result get away with a lighter gauge spoke and so negate some of the weight disparity on the wheelset. The Crest also does not have the extra wall internally that you find on the Arch or Flow rims. Nevertheless, the crest is still a good rim for a light rider on a light XC course.

I do not sell the Alpha because the crest is such a significant upgrade with no significant weight penalty.