The lid and straw are dishwasher safe on top rack. The pictures on the cup itself wear off with each run of the dishwasher so I would recommend hand washing only. We have four young kids and these go everywhere with us (car, park, zoo, museums...). If the lids are tight it's hard to drink water out of them, but if you loosen the lid they leak. Our oldest is 5.5 and he does better so these are probably good for older kiddos.

Truly love the Zak cups especially the metal ones! These are actually leak proof and better yet, they come as a 2 pack! I love the flexible straw so if my toddler runs with it he won’t get hurt like other cups. The designs are so cute! These are the perfect milk cups for us and use them daily!

I’ve received the Zak Designs 12-oz. Stainless Steel Double-Wall Tumbler for Kids with Antimicrobial Straw, 2-Piece Set two weeks ago. I couldn’t be more happy with the product. It’s winter, it’s come at perfect time. I recommend this product to all my friends and family.

My grandson loves these cups. He just turned four. I have not had any leakage when dropped, and it keeps the cold drinks cold. He sucks them like a straw. I hand wash, and use a bottle brush to clean the straw part. It says the top part is dishwasher safe, but I clean the detached straw, and straw opening on the lid with a bottle brush. You could use the dishwasher for sanitizing.

My kids love these cups! They don’t feel like a sippy cup so it makes them feel more grown up. I’m always carrying a cup that has a straw and they feel like big kids carrying their cups with straws. I can take a big sigh of relief because I know that we won’t be spilling water everywhere! Designs are adorable. Highly recommend!

I had ordered these for my grandchildren age 2 & 8. At first I thought they might not like them, but they both loved them. They easily fit in the car's cupholder and the straw make it very easy for them to drink. They loved the Star Wars design and I love that they don't spill. Great product.

My son uses different "spill-proof cups", but many still leak or spills if he accidentally knocks them over. However, this Zak 12 oz. Tumbler has proven to be a true Leak-Proof Cup. I chose this particular cup because I really loved the cute design & bright colors, but I also wanted a insulated cup that could keep his drinks cold no matter the season. This cup does a wonderful job at that! My son really likes the straw top and it's easy for him to drink from. I haven't had any issues with the cup leaking and it's very simple to clean and fill with liquids. Out of all the cups we've tried, this has definitely been a favorite and I plan on getting a more.

Started leaking on first use and only continued to leak worse

Rusted only 5 weeks after purchasing it, and average usage would be less than 1/3 of the total days.

Leak proof, good size for nighttime drinks for my 5&6 year olds, and you can’t go wrong with BLUEY! My kids LOVE that show, I kind of do, too ;)