Which passive infrared sensor should I get for the book: Arduino-A Quick Start G

I bought an Arduino and the book Arduino A Quick-Start Guide for my daughter for Christmas. I’m trying to buy all of the parts she needs and one of them is the passive infrared sensor, listed as Radio Shack part #2906724. When I went to RadioShack’s site, they don’t have that part number. Can someone please recommend a suitable replacement? I’m already making an order with Jameco and Digi-Key, so a part at one of those would be nice.

Thanks in advance for the help, hope I put this in the right area.

Looks like the PIR sensor has been replaced:


Parallax PIR Sensor Model: PIR Sensor | Catalog #: 276-135