Comparison : Item # M-4-BR, Orifice Assembly - Adapter, Unified Thread, Type M
Item # M-5-BR, Orifice Assembly - Adapter, Unified Thread, Type M
Item # M-6-BR, Orifice Assembly - Adapter, Unified Thread, Type M
Item # M-7-BR, Orifice Assembly - Adapter, Unified Thread, Type M
Item # M-8-BR, Orifice Assembly - Adapter, Unified Thread, Type M