water cooling manifold
you need this two things
https://de.aliexpress.com/item/1005008186908940.html?spm=a2g0o.order_list.order_list_main.189.68035c5fdkXKsP&gatewayAdapt=glo2deu
https://de.aliexpress.com/item/32971006524.html?spm=a2g0o.order_list.order_list_main.10.6bda5c5f0MfgKw&gatewayAdapt=glo2deu
The author marked this model as their own original creation.