Wooden comprising an upright 100 mm high , with V shape slot to hold a convex or cancave lens , mounted on rectangular base 100 x 50mm.
Wooden to take lenses or mirror up to 76 mm diameter. Comprising an upright 100mm high , with V shape slot to hold a convex lens , mounted on rectangular base 100 x 50mm . An index mark is engraved on each end of the base.
