Original Apple, fully tested PowerBook 145B daughterboard containing the 25 MHz 68030 processor, 4MB of soldered onboard memory and one memory slot. Although interchangeable with the 145 daughterboard, the 145 board only has 2MB RAM soldered although the total addressable memory of the machine is still only 8MB. This processor card will work on the Powerbook 140, 145, 145B and 170.