Kaaz 1.5-way limited-slip differential is the most common viscous LSD upgrade option in performance built Lotus Elise or Exige (2ZZ-GE), as well as the Toyota SW20 (3S-GE), MR-S (1ZZ-FE, 2ZZ-GE). It is referred to as a 1.5-way because it functions under acceleration and to a lesser extent under deceleration.