and that's all I use...the best one, the oringal, #02. Now it just came out in a fractional grade, but for now ZeroTwo is the one. CTO's however come in 1/8, 1/4, 1/2, 3/4 and full, perspectively 3410, 3409, 3408, 3411, 3407--the 3411 filter takes daylight and turns it into tungesten, so if you put it over your flash, your light is now tungsten without the heat.
In a greater scenario, put 3411 in front of your flash, white-balance to tungsten, your subject will be just fine and your sky will go deep-blue...thanks, rg sends!
(From the last Virgin Islands Workshop (we still have two slots for Nov. 2006), Playboy Model Laura F. with bastard amber #02 in front of the Hensel ringflash with a Hensel Sunhaze.)