The AD-291 2U industrial rack mount computer may be only 2U high, but it incorporates 6-slots enabling the AD-291 to accept a variety of single board computers and other PCI/ISA cards. The locking front door protects both floppy and CD-ROM drives in harsh environments, while the built-in fan keeps things cool. The design of the AD-291 allows for horizontal installation of full-size single board computers and room for add-on cards. Its an excellent choice when you need a compact computer that’s big on performance and convenience.