Cisco PIX Nating

Hi There!
I am trying to find out how to convert the nat entries from cisco pix to checkpoint.Could someone please explain the following natting entry in Cisco PIX firewall in ver 6.3

global(outside) 1 10.20.30.40
global(inside) 1 interface
nat(outside) 1 155.166.0.0 255.255.0.0 outside 0 0
nat(inside) 1 0.0.0.0 0.0.0.0 0 0

Your kind help is highly appreciated.

Thank You.