[magnetic] second layer (can put 2 pairs of shoes)
"Magnetic" three layers (can put 3 pairs of shoes)
[magnetic] six layers (can put 6 pairs of shoes)
"Magnetic" nine layers (can put 9 pairs of shoes)
[buckle] second layer (can put 2 pairs of shoes)
[buckle] three layers (can put 3 pairs of shoes)
[buckle] six layers (can put 6 pairs of shoes)
[buckle] nine layers (can put 9 pairs of shoes)
[double row magnetic suction] six layers (can put 12 pairs of shoes)
[double row magnetic suction] nine layers (can put 18 pairs of shoes)
[three-sided magnetic penetration] six layers (can put 12 pairs of shoes)
[three-sided magnetic penetration] nine layers (can put 18 pairs of shoes)