Hey aquarium owners! These little clear clips are total game-changers for keeping your fish tank secure. You get 20 pieces in the pack, which is plenty for most setups. They're made from durable acrylic that's crystal clear, so they barely notice once installed. The inner width is exactly 6mm, perfect for tanks with glass thickness between 5-6mm. Installation is a breeze - just snap them on and they hold your cover firmly in place. No more worrying about fish jumping out or pets escaping! They work great on all kinds of tanks - ultra-white aquariums, straw tanks, even turtle and snake enclosures. The best part is they take up almost no space and don't ruin the clean look of your rimless tank. When you need to clean the tank or change water, they come off easily but hold tight during normal use. Seriously, if you've ever had a fish jump ship or need to keep curious pets contained, these are worth their weight in gold. They help keep evaporation down too and prevent dust from getting in your water.