Difference between this boot and the Pro 18 is this model doesn't have the top of foot velcro strap for securing foot tighter. NNN outsole. 

Inside length of the Skate Pro 17 model measured by us with tape measure:

38 Euro: 9 3/8"

39 Euro: 9 3/4"

40 Euro: 10"

41 Euro: 10 1/4"

42 Euro: 10 3/8"

43 Euro: 10 1/2"

44 Euro: 11"

45 Euro: 11 1/4"

46 Euro: 11 1/2"