Blenpar 18oz Cup with Sip N Seal Lids Compatible with Nutri Ninja Auto-iQ Blende These parts only Compatible with 900W 1000W Nutri Ninja Auto-iQ Blenders. Measure the outside diameter of the blade or cup and it must be 3.94" which is almost 4" None of these part fit the Ninja blenders that take 16oz cups. They do NOT fit Magic Bullet, Nutribullet This is an aftermarket item made to fit Nutri Ninja Blenders Fits Nutri Ninja Kitchen Systems Auto IQ and Duo Blenders. Compatible with the BL450 Series, BL480 Series, BL640 Series, CT640 Series, and CT680 Series such as BL480 BL481 BL482 BL490 BL640 BL680 BL450 BL482 BL682 BL642 BL640 FEEDBACK: We will leave feedback after receiving a feedback. If for any reason you are dissatisfied with your purchase, please contact us immediately before leaving any NEGATIVE FEEDBACK so we resolve whatever issue you may have. 100% Customer satisfaction! Sales Tax: CA residents will be charged Sales Tax SHIPPING: Orders are usually processed within 24-48hrs. All weekend purchases are shipped Monday. CONTACT US: Have any question(s) contact us in contact seller. RETURNS: Returns are accepted but must be authorized in advance.