Bushwalk Australia

Instructions indicate there should be a bit of play and the insert should slip around with your foot to the tune of 2mm(?).
I cant see it mattering much but does anyone have any experience?
At the moment mine are cut still snug.

depends how tightly it fits in the shoes, it fits in mine and doesnt seem to move. but given its a generally shinny surface underneath i'd expect it to shift if it doesnt fill out the entire shape of the inner sole