P18420-B21 240GB is an SSD type hard drive which can fit 240 GB of data. The form factor is 2.5" which is common for SSD drives.
From ServersPlus
HEWLETT PACKARD ENTERPRISE 240GB SATA RI SFF SC MV SSD
Compadvance
HP e 240Gb
This product is also available at 2 unverified merchants.
Too expensive? Get a notification as soon as the price drops.