This is Progressive Suspension's long-awaited 5th Element Air rear shock, spied on the Santa Cruz stand at the Fort William World Cup. Santa Cruz importers Jungle have started to receive shocks for OE fitment to bikes, and Progressive importer TF Tuned should have shocks for aftermarket sale any time now.
It's certainly an impressive-looking bit of kit, and the lack of weight is striking - we weren't carrying scales around with us in the pits but it's substantially lighter than a Fox AVA, for instance. Progressive claim a sub-200g weight, and that's very light indeed.
The air variant of the shock doesn't have all the bells and whistles of the coil shock. It's got Platform Damping Control, adjusted via a second air valve, but it doesn't have bottoming control or adjustable beginning and end stroke firmness. We don't think that these are things we'll miss, and having seen people get in a right old pickle setting up coil Fifth Elements a little bit of simplification is probably no bad thing.
Prices are yet to be confirmed but are likely to be around £310-330. More information from TF Tuned Shox.