Complete stock set of the HK416c stock that has the functioning recoil (next-gen). Set costs brand new around 3k. I’m selling mine nearly half that amount.
https://eagle6.co.uk/shop/catalog/product/view/id/5926/s/tokyo-marui-hk416c-complete-stock-set-for-m4-hk416-next-generation-recoil-shock-series/