this fit my ninja BL770 perfectly. i was afraid to buy this because of the talk of leaking and what not, and i almost bought my replacement cup from the ninja website until the shipping was bumping the price to almost 20$ for 1 cup. so i took a risk on this one and i'm glad i did. it fit the blending cap and the ninja itself just fine. made 2 smoothies already!My wife lost one of our Ninja Blender Cups and I thought the world was going to end. But then I hopped on Amazon and found this. At first I wasn't sure if this was a real Ninja cup or an off brand, but it is the real thing! The ones that came with our blender are darker and this is more clear, but works exactly the same! I will be ordering more!!Not exactly the same as the one that came with the blender (and exploded making a smoothie---Ninja said "hope you weren't hurt") but it does the job and has not exploded as of yet.cup works great, but the lid is useless. I thought it would be a lid that sealed so I could take the cup with me buts basically just a sippy lid that won't even prevent spillage in a car cup holder.Good quality, only gripe is there is no measurement labels on the cup.Seals occasionally leak when cups are used for mainly liquids. They don't get quite as good of a seal with the single blend blades as the original cup that came with the blender.I bought four more to go with the original two that came with my Ninja. Even though I now blend six individuals instead of one large pitcher, it is convenient to have each in a serving glass already. I can also individualize for taste preferences.It's a great cup but I'm looking for a replacement cup to fit on my Ninja. This won't work for that as the opening is too small.El producto está muy bien pero se tardó como 3 meses en llegar. Pedí cancelación y nunca me lo cancelaron y llegó hasta después.