1g/2g dual piston caliper bore difference?

[PlanZero]

I always thought 1g and 2g dual piston calipers were the same except for the banjo bolt fitting. I was keeping an eye out for a front left caliper on rock auto and I found one for a 1g but it says 42mm, and the 2g says 43mm (same manufacturer). Can someone please confirm this?

 

[PlanZero]

Well to answer my own question yes there's a difference 1g on left, 2g on right. So the description was actually backwards. In fact the bore appears to be the same, but the 2g pistons are smaller with a double layer seal. Both brackets are identical.

You must be logged in to view this image or video.

 

[lasthope05]

You need to remove the boot and pull the pistons out to measure them. You cant tell anything by just looking at them.

 

[PlanZero]

Well I thought the picture was fairly obvious. The 1g is bigger. It's a moot point really, I have sets of both. This is for future reference.