F23Power

Weird looking piston

Hi guys, Im new to Honda-Tech and in the process of building a F2B into my EG 4door( we call it Ballade). I'm using a F23, this particular engine is a F23Z4, it came out of a Odyssey and I'm giving it a refresh. As I've searched for compression ratios on the different f23's I've never came across any f23 using this specific piston, also a search on the specific code (F23Z4) comes up with no info on specs apart from it being from an Odyssey.
I was hoping you guys could help me out on any info or any link that I might have missed please? Where I'm from it's difficult to get parts without importing from another country, I initially wanted to swap in some K20 pistons, but that is of course like looking for chicken teeth,lol.

Any help would be much appreciated.
Thanks in advance