Hardie Board with Batten Siding System

Nice job look pro , what kind of nail gun are you using and what tipe nail , thank you

Looks mint .I have a customer who changed their mind from using hardie lap siding and now wants board and batton but the entire shop that was built on 24 o/c so all I have to fasten to is 1/2 standard ply . How would you fasten ?
smaller nails and a lot more 🤷‍♂️

What kind of material is that?