3 Bar Tri Glide Sliders Buckles Fasteners for 38 mm / 1.5 in Webbing Strap, Backpack, Bag, Accessories, Black Delrin Plastic (Pack of 10). To ensure correct buckle size, buckles are measured by the width of the material that fits through them. For example, if you have 25 mm / 1-inch webbing you will need a 25 mm / 1-inch buckle. Buckle Size = Webbing Width. This slider buckle is made of plastic material which is durable and lightweight, so can be used for long-lasting purposes. It has 3 bar sliders which help the buckle to adjust easily. You can change the length of the strap when it's too long or too short. This tri-glide slider easily replaces broken sliders on your sports bag or backpacks. Tri-glide slider buckle is ideally used for webbing straps, belts, backpacks, luggage bags, rucksack collars, handbags, fasteners straps, purses, bag accessories etc.