BlenderBottle Brand Product BPA Free Genuine Insulated 24 Hours Cold Detachable Loop Double-Wall Vacuum-Insulated Stainless Steel Stain & Odor Resistant Leak Proof Guarantee BlenderBall mixes as you shake: Our proprietary mixing system utilizes the BlenderBall wire whisk - found only in BlenderBottle brand shaker cups - to delivers smooth shakes in seconds. No batteries, no cord, no hassle. -Double-wall Vacuum Insulation keeps drinks cold for up to 24-hours -Twist-on Cap for a worry-free seal -Detachable Carry Loop disconnects at base to attach keys or connect to gym bag -BlenderBall wire whisk mixes as you shake