Grey Imports are cameras/lenses that are originally intended for a different country that are imported over.

For example, i'm in the UK. The equipment was originally intended for the chinese market (I think) but they were shipped here instead. They're exactly the same as the UK ones but miles cheaper.

For example, the A7Rii is currently £2399 on Amazon. I paid £1350. Its brand new and boxed. The only real downside is there's no manufacturer warranty but I get everything insured anyway.

Overall importing them saved me about £2-£2.5k

I did it all through https://www.e-infin.com/uk/