I think your are looking at Speedtech's own line of gears, which appear to be modeled after Xenon Racing gears. These are not PRS brand gears. The gears you are looking at seem to require an adaptor for the T2. PRS gears are a direct bolt on for the T2- no need for an adaptor.
Also, the spur gears you are looking at are white in color. PRS gears are machined and I believe only come black in color.