Don't trust your data on just any disk. Our disks are highly tested, Retail Box, Hot swap Drive assemblies, to add to or directly replace a failed HP A6541A A6541-63001 A6541-69001 . NOT BULK Package, NOT Refurb. This 37GB Low Profile (1") Hot Swap Drive is 15,000RPM and state-of-the-art design, a 4MB Cache and a Ultra320, Ultra3 and Ultra2 interface compatable with HP Disk System DS2100 and DS2300.