Review on 🍹 Nutri Ninja Blender Series Compatible Grey 2 Pack Sip & Seal Lids: BL660, BL663, BL663CO, BL665Q, BL771, BL773CO, BL810, BL820, BL830, QB3000, QB3000SSW, QB3004, QB3005 by Heather Welsh

They make my smoothies easier to transport and prevent spills. The design of the cup is just great. I wish they were a little more stackable to save space in my closet. Although the lid design itself isn't the best. They're really hard to take off and I'm afraid I'll break the little valve that closes the drinking hole if I take them off. They are also very unpleasant to drink from; an oddly shaped hole in the lid. All in all, I can drink my smoothie in the car on the way to work and toss it in my lunch bag without worrying about leaks, so I'm happy.