According to the manufacturer's website, you need the EKWB EK-FC1080 GTX 1080 Strix for the 1070 Strix OC (Unfortunately, only the version in nickel is available here at Digitec).
https://www.ekwb.com/shop/ek-fc1080-gtx-strix-nickel
https://www.ekwb.com/configurator/waterblock/3831109831410
Besides the Founders Editons, it is also compatible with all GTX1070s with reference design. You can find a compatibility list for all EKWB products on the EKWB website.