Why is ‘375-6075’ printed on some NEXO KNIGHTS™ stickers?

You might have noticed that some stickers in NEXO KNIGHTS™ sets have ‘375-6075’ on them. These numbers are actually quite important in LEGO® history. The first LEGO® Castle set launched in 1978 Europe, with set number 375. The first Castle set in North America, released in 1981, was set number 6075. NEXO KNIGHTS™ was a cool update on the classic Castle theme, so the designers added a little bit of history into the sets.