The Horse Pilot Fit Kit aka Light Pack kit allows you to wear the Horse Pilot Airbag Vest alone. It is composed of a double zip on mesh to close the front of the vest and a protection for the gas cartridge. (Choose the same size as your Airbag)
Please note that you cannot use 2 KITS together to create an XXL.
The Airbag did not get certified with this type of adjustment set up, Horse Pilot cannot guarantee the safety of it.