Is it the Gates Carbon belt drive system? http://www.carbondrivesystem.com/
Ventana Mountain Bikes have produced frames in both 26" and 29er wheel size with a rear axle slide system that will come apart and allow the belt to pass through the seat stays.
So new they are yet to feature on their website http://www.ventanausa.com/index.html
but they are essentially modified El Toro or El Commandante frames with without the EBB but now with a slider.
I have one of the first production El Commandantes already a great 29er single speed made better with the belt drive.
Positives; quicker, lighter, stronger, longer lasting, all weather mud loving, low maintenance, cool!
Negatives; less gear ratio's ATM, but with a couple more belt lengths in the pipe line to solve that.