Rubik 5x5x5 "Professor"

Purchased from Rubik's.com 2006;
patented by U. Krell 1986.

(plastic, 2.75 inches)

Purchased from Mefferts 2007;
uses the Eastsheen mechanism.

(tiled plastic, 2.9 inches)

Mefferts "Mini Professor" 2007;
uses the Eastsheen mechanism.

(plastic, 2.3 inches)

Made by V-Cube 2008;
patent application by P. Verdes 2007.

(plastic, 2.5 inches)

Further reading:
Meffert's Page, from: http://www.mefferts.com/puzzles/profsol.html
Jaap's Page, from: http://www.jaapsch.net/puzzles/cube5.htm
McFarren's Page, from: http://www.geocities.com/abcmcfarren/math/rp/RubPro1.htm
Monroe's Page, from: http://www.geocities.com/alchemistmatt/cube/5by5cube.html
Wikipedia Page, from: http://en.wikipedia.org/wiki/Professor's_Cube
Krell Patent, from: www.uspto.gov - patent no. 4,600,199
Li Patent, from: www.uspto.gov - patent no. 6,129,356
Verdes Patent Application, from: www.uspto.gov - patent application 2007/0057455