The Boost Spacer could be a great help, if you have 2 or more bike which have 15mm thru axle systems, and you need to carry both 15x100mm and 15x110mm bikes without changing the fork mount on your bike rack! Simple insert your skewer through your fork and 15mm fork mount, then when the bike already has some support from the fork mount, place the spacer in between end of the fork mount and the fork, then pushing the skewer through and screwing it tight.