There are two main types of boa systems – Single Boa and Double Boa.
These systems often have an inner tightening system similar to traditional lacing systems but the outer boot is tightened using a knob that you twist to pull a system of wires tight across the boot.
Single boa systems have one knob for the whole boot. Double boa systems have one knob which controls the lower boot and one knob that controls the upper boot.
Typically double boa system snowboard boots are a bit better for controling pressure points. Like traditional laces you can control the bottom tightness with one BOA and top tightness with the other BOA.
Benefits of BOA
- Can get your boot super tight without much effort
- Easy to adjust tightness on "the run" or the lift
Cons of BOA
- Can cause pressure points if you don't find the right fit for you or you tighten the boot too much
- If you break a BOA you will need to find a snowboard shop to fix it for you. Most shops carry the replacement parts for BOA nowadays but it will take some time out of your day.