As the name implies this is a combination of a pulldown and a pullover.  It is a great exercise for the stretch and the contraction of the lat muscles.

1.Grab a decline bench
2.Pull it up to a low cable pully
3.Grab a close grip row attachment
4.Lay down on the bench and have a training partner hand you the attachment
5.Start with the stretch and then pull the attachment towards your upper chest.
6.Squeeze at that point then return under control to the stretch position.