> For the complete documentation index, see [llms.txt](https://paramita-inc.gitbook.io/sinra/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://paramita-inc.gitbook.io/sinra/7.-marketplace/7-4.-secondary-sale.md).

# 7-4. secondary sale

Regenerative NFTs are issued in accordance with the ERC721 standard, making it possible to sell them on various external services such as OpenSea. Additionally, SINRA is planning to develop a marketplace in the future to enable secondary sales as well.

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