These ND9 glasses are Adjustable Tint Polarized Round Sunglasses, featuring a rotating lens mechanism that allows you to manually control the tint darkness. 

Features 

• Adjustable Tint: Lenses rotate to change brightness levels, similar to camera ND filters. 
• Protection: Equipped with polarized lenses and UV400 protection to reduce glare and block harmful UV rays. 
• Design: Round, retro-style frame  constructed from metal. 
• Usage: Suitable for various lighting conditions and outdoor activities like driving or fishing.