The unique end plate on this rack allows you to create agar slant tubes at either 5° or 20° depending on which side you use. To create the slant tubes, simply autoclave the media tubes while they are in the rack, and after autoclaving, set the rack on the bench at the desired angle. The media will harden with a consistent slant. The rack is also useful for incubating liquid cultures on a slant. In addition, it is keyed with numbers and letters for identification, is stackable, and does not float in water baths. It will hold forty 16 mm tubes. Size: 11 1/4" x 4 1/2".