These liners are a bit tough to get into the boots, buy they do work with Totes boots of the same size (youth 3).  They would not fit into Itasca size 3 boots, which are just a hair smaller.  They are kid-approved for comfort and warmth, and they don't make the boots too tight.  I trimmed around an inch to an inch and a half off of the tops so that they wouldn't stick out too much.  These liners are high quality and are much thicker and warmer than the liners that they are replacing (thanks to my 9-year old losing one of his original boot liners at school.  How on earth do you lose ONE of your boot liners????).  I also like the reinforced heels.  The original boot liners were already starting to get holes in the heels.  These liners look like they will last longer, unless he loses them.