Safety Eyes & Noses are used in toy-making. Once fastened to a fabric, they will not come off, unless the fabric is torn apart completely around it. Please keep this in mind when fastening it to your project - there are no second chances once the washer is placed.
The washer is meant to have an incredibly tight fit - sometimes you have to warm it, to soften it, in order for it to fit on the screw-back of the eye or nose.
Larger safety eyes may come with a removable piece of film on them, to protect them from being scratched in transit.
For size comparison purposes, the eyes are pictured on a 100g ball of worsted weight yarn.