mp3bu

Thanks also FYI I found a really good explanation of this:

"The PAC investor is scheduled to receive fixed principal payments (the PAC "schedule") over a predetermined period of time (the PAC "window") through a range of prepayment scenarios (the PAC "band"). The schedule will be met only if the underlying mortgage-related collateral prepays at a constant rate within the range assumed for the structuring of the PAC."

I was confusing the PAC band with the PAC window. ANyway thanks.