1/2" Air Mixer Valve Come with 1/2 Brass Adapter, both sides are 1/2 NPT female thread, so that the air mixer valve is able to connect to both male or female thread burner.The air mixer valve is only suitable for low pressure fire pit system,please don’t use it in high pressure fire pit system causing damage to your equipment.，You need the Air Mixer when you using liquid propane or some other combustible gas for outdoor fire or fire pit. The liquid propane can not burn very well without the air, so in this time you need the air mixer to mix the liquid propane and the air to make fire burning well. I think our Air Mixer will help to burn the fire well.