If you have an older MK200 first stage and wold like to use it for colder conditions ? This can seal your first stage up and protect it from the cold !!
Make sure that you get a reputable service technician to service your regulators. Aqua Sport Scuba Center Inc takes no liability or responsibility for the service work done with the sale of any service kits. It's up to you to be a responsible adult and understand your risks and responsibilities. Training and experience is very important. Play safe !