Pentium II and Pentium III processors are as identical as Pentium 4 2.0 GHz and Pentium 4 2.0A GHz Processors.

However, there is a package difference. Early 66 MHz FSB Pentium IIs, such as that one, have SECC packages (Single Edged Connector Cartridge). Later model 100 MHz SECC2 (Single Edged Connector Cartridge 2) Pentium IIs (including Eric's), Pentium IIIs and Pentium III Xeons are all compatible with a motherboard that can support the ratio; usually by BIOS update. The best Processor in this package would be a Cascades/Pentium III Xeon 1 GHz / 256 kB L2 Cache. I believe the fastest SECC Pentium II is 333 MHz.

Anything faster than that would be in PPGA (Plastic Pin Grid Array) or FC-PGA (Flip-Chip Pin Grid Array)/370 package.

Edit: I didn't notice you had a 266 MHz model there, sorry.