What is the difference between Inon External Auto Diffuser and the old Diffuser

Inon has a two different diffusers for the 240z strobe. One works with the auto mode and the other does not. Does anyone know what the differences of each are. I have the non auto version, can I enlarge the sensor hole to be able to use the diffuser in auto mode? I there any other differences?

http://www.inon.jp/products/strobe/diffuser/z240d2000.html

Inon External Auto Compatible -0.5 Diffuser Blue

New diffuser

old diffuser

I want to thank Inon and their support, they we very helpful!!!

Inon said there is a difference in the diffusers where the proper light is blocked when using auto external so just making the hole larger will not help.

I would imagine a ring of permanent marker on inner/outer surface around the sensor hole would 'mod' the old diffuser just fine.