Objective and Eyepiece covers for Binoculars

Those are replacement covers for the Garret Optical 10x50 Gemini binoculars. The barrel of the objective has the external diameter of 61.8 mm in it's widest point, and the eyepiece's rubber is 45.1mm.
The diameter of the covers is fine-tuned to fit firmly on that specific model - but I believe it can be easily scaled up/down to match other models as well.