https://www.amazon.com/dp/B002WD1MY6?tag=sortagotta-20

another one: https://www.amazon.com/Moeller-Roto-Molded-Marine-Battery-13-06/dp/B000MTI1GE

Try searching for 8D battery box, that seems like it may describe the size.

Noco 8D box- https://www.amazon.com/dp/B002WD1MY6?psc=1

Blue sea systems battery switch https://www.amazon.com/dp/B07CT4NXMQ

make sure you get a key with each switch, The keys cant be removed if battery's are turned On. Only in the off position do they come out.

2x200ah plus Battery's (sold out last i looked)- https://www.amazon.com/gp/product/B08P6HH4WK

Also the Silicon pads i used under battery and lid hardware. sold for pets but pure Silicon is pure silicon, heat resistant.- https://www.amazon.com/gp/product/B07SQ3LN4T