When you get your new FlexHorse boots, back strap and pastern strap are closed position like in the picture.
Soft but durable gaiter is attached to the boot with small rivets. You can open the rivets and chance the gaiter when needed.
Before you put the boot on, open the outside of back strap and pastern strap. Inside of the back strap can remain closed.
Put the boot on by twisting from the sole of the boot, not pulling from the gaiter.
Close the pastern strap keeping 2 fingers between leg and strap. Strap should be snug but not tight.
When you close the straps, you feel how the rivets will sink in to the holes of the straps. Just push the holes from outside and rivets will come thru the holes.
If the back strap is very long from the outside, you can make it more even buy opening the inside strap and balance the strap.
If the straps are so long that they touch the ground, you can cut away extra part.