Hello,
The Pro series has more capacity and features, which is commonly used in different scenarios.
OptiX OSN 1800 V
The Huawei OptiX OSN1800 is a series of box architecture MultiService Optical Transport Network (MS OTN) transmission equipment that supports Time Division Multiplexing (TDM), packet, and Optical Transmission Network (OTN) services over a metro or campus optical network.
OSN 1800 V Pro
OSN 1800 V Pro is a highly integrated all-optical transport platform designed for enterprises. The OSN 1800 V Pro can be widely used in industries such as energy, electric power, transportation, education, and finance that are crucial to the national economy and people's livelihood.
You can see the full specs of each in the guides attached to this reply.