Product review (3 stars): Way Overpriced
Consider the material cost and the rate at which these are cranked out. Yes they work fine, but at > $9 each they are too expensive. Consider as an alternative, a 25-pack of basically the same thing (slightly higher durometer but they work great) from McMaster-Carr, Buna-N O-Ring, 3 mm width, 84 mm ID for $11. Yes that's right, 95% lower price. This would be McMaster number 9262K759.