Key transmitters

[m4rkw]

My key transmitter is falling apart so I'm considering getting a new OEM one. I have an aftermarket one but it's not very good quality and there's very little choice for a japanese import.

My dilemma though is that there appear to be three transmitters listed for my car:

http://japan.toylexparts.com/decode/pr_num/8907148140
http://japan.toylexparts.com/decode/pr_num/8907148150
http://japan.toylexparts.com/decode/pr_num/8907148420

with no obvious way to distinguish them. Google hasn't helped. Anyone know how I can figure out which one I need? Are they 2-button/3-button variants or just all interchangeable?

[m4rkw]

Managed to get an answer from Lexus, it's the first one for my car. Ordered.