What is the fine-grained topic of the following text: The 4 x 4" Neutral Density Filter Starter Kit with 58mm Adapter Ring from Hitech includes 0.6 and 0.9 neutral density filters made from high quality optical resin as well as a 4" filter holder and 58mm adapter ring. Only return the topic.
Neutral Density Filter Starter Kit with 58mm Adapter Ring from Hitech