Rubik 4x4x4 "Revenge"

"Rubik's Revenge";
Patented by P. Sebesteny 1983.

(plastic, 2.5 inches)

Mefferts "Rubik's Master" 2007;
uses the Eastsheen mechanism,
patented by C. Li 1999.

(plastic, 2.3 inches)

Further reading:
Jaap's Page, from: http://www.jaapsch.net/puzzles/cube4.htm
McFarren's Page, from: http://www.geocities.com/abcmcfarren/math/rr/RubRev1.htm
Helm's Page, from: http://www.helm.lu/cube/solutions/revenge
Hardwick's Page, from: http://www.speedcubing.com/chris/4-movelist3.html
Hardwick's Speed Page, from: http://www.speedcubing.com/chris/4speedsolve.html
Jeays Page, from: http://jeays.net/rr.htm
Rubiks.com booklet, from: http://www.rubiks.com/World/Rubiks%20downloads.aspx
Rubiks.com assembly page, from: http://www.rubiks.com/World/Rubiks%20downloads.aspx
Wikipedia Page, from: http://en.wikipedia.org/wiki/Rubik%27s_Revenge
Sebesteny Patent, from: www.uspto.gov - patent no. 4,421,311
Li Patent, from: www.uspto.gov - patent no. 5,992,850