Part number for "big box" Speedmaster black NATO?

Does anyone know the item code/part number for the fully black NATO that comes with the 2014-2021 Speedmaster please?

I used the NATO for 7 years and ruined it so would like to get another to just store back in the box unused.

Thank you - I remember when the set first came out you couldn't actually buy the NATO on it's own and they only sold a similar black one but it had grey edges, good to see it's readily purchasable now.

Also, wow they are extremely expensive for what they are at £170.