Combination of 4 c-rings, 1 on each tarsus, 1 on each tibia.
note 1 : this scheme in use since 2006.
note 2 : c-ring on left tibia is either green, white, red or yellow.
note 3 : c-ring on right tibia or either tarsus is white, green, lime, black, red or yellow.
note 4 : metal ring can be on either tibia.