Dear customer, please note that items Western Digital WD Ultrastar 18TB 3.5' Enterprise HDD SAS 512MB 7200RPM 512E TCG P3 DC HC550 24x7 Server 2.5mil hrs MTBF 5yrs WUH721818AL5201 are currently listed as pre-order/on order. You can continue to place a backorder and it will ensure earliest allocation when these products are available. Our team will contact you to notify the expected ETA. Thank you.