50Material:Metal. Inner Diameter: M25 x 0.75. Actual Extended Length: 6.5mm. Package Included: 1 x M25 Extension Ring only (objective lens and other accessories are not included).
Outer Diameter: M25 x 0.75. Thread Height: 4mm. Full Height: 10.5mm.
Professional and practical design with beautiful appearance, easy to carry and use.
Usually used in laboratories, schools, teachers, sample observation, eyepiece protection, etc.