PG-01Inner Size : 11cm，12cm，12.5cm， 13cm ，14cmWhen you make order，please corresponding Size:3.5-4.5-5-6-7If you want 11cm，order size 3.5， if you want 12cm， order size 4.5， if you want 13cm，order size 6，if you want 14cm，order size 7 (Please measure baby feet before you order， For example，If baby feet is 10cm，suggest take shoes size 10cm+1cm， You can choose size 3， baby is growing day by day， little bigger make baby feel Comfortable)Season : Summer spring and autumn