. mounting system: complete with gasket to securely hold the insert in place, which allow for slight irregularity in the hole. . The rubber ring is inserted into the side of the perspective then directly into the handicraft. . Features: the quartz clock insert features a clear plastic lens, and black roman numerals, . . Front diameter 97mm, rear diameter with rubber ring 91mm, thickness 33mm(excluding border, battery cover, height of knob when adjusting) . Power: require 1 piece AAA battery (not included); Warm note: clock is intended for indoor use only, not weather resistant. Description: - Front diameter 97mm, rear diameter with rubber ring 91mm, thickness 33mm(excluding border, battery cover, height of knob when adjusting) - Features: the quartz clock insert features a clear plastic lens, and black roman numerals, . - mounting system: complete with gasket to securely hold the insert in place, which allow for slight irregularity in the hole. - The rubber ring is inserted into the side of the perspective then directly into the handicraft. - Power: require 1 piece AAA battery (not included); Warm note: clock is intended for indoor use only, not weather resistant. - Material: Metal, Plastic Package Includes: 1 Piece Quartz Clock Insert Note: Since the size above is measured by hand, the size of the actual item you received could be slightly different from the size above. Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same.