Energy Futures ETFs

Hello:

Are there future-based ETF's for which the underlying futures contracts are 2-Month, 3-Month futures contracts for nat gas or crude oil? Or are they just 1-Month futures like the ones in USO's?

Thx

 

USL is a 12 month futures based ETF for oil. Check the profile on Yahoo or elsewhere.

 

Ok, good. And what about all the future horizons in between... 2-Month, 3-Month, ... 6-Month futures contracts? Are they used in other exchange traded funds, or energy futures swaps? Thank you much.

 

DB0 uses , i think , 2 and 3 mo. But not much volume there.
DBC is better, but has more stuff.

 

Do we know how often they roll the front contracts of these futures?

 

How is the trading in USL, volume seems to be light?