I bought these caps while looking for valve caps for my car. Please note that the product is not the one shown in the picture. The product has a flat end with a nipple. The actual product is stronger, heavier. These aluminum plugs look flimsy and flimsy in the photo. I like the strength and the caps have some weight which makes them thicker and weather resistant. I gave some of these away to my friends and if I use all 50 I will definitely buy 50 more!