WD 18TB ULTRASTAR DC HC550 3.5 inch Enterprise SATA 7200RPM high performance with 512MB Cache
https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/data-center-drives/ultrastar-dc-hc500-series/product-manual-ultrastar-dc-hc550-sata-oem-spec.pdf
https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/data-center-drives/ultrastar-dc-hc500-series/product-manual-ultrastar-dc-hc550-sata-oem-spec.pdf