GuidecraftSensory Rainbow Blocks - 18 pc. Set: 6 Shimmering Water, 6 Sand and 6 Crystal Bead Blocks, Construction Building Toy Set for Kids - Stacking Blocks

I was very impressed when we received the blocks. They appear to be well made and we love all of the different colors and types of media inside. We're using these in addition to the traditional wooden blocks we already owned to add color, etc. We haven't had any issues with any blocks leaking. We do closely supervise the kids while they play with them to make sure they're not being thrown about as there is of course a possibility they could break/leak if handled roughly. No complaints here, great product!

I made the mistake of not opening these until today. I purchased them at the end of the year, so the return window has passed. Our toddlers played with these for the morning, then our teen noticed this crack in one. It later presented condensation, so I know air is getting in, which means it’s just a matter of time before it starts to leak. Not very durable if it can be cracked this easily by a couple of toddlers (less than 18mo.) with no sharp instruments.Update: after putting them up for over a month, we took them out today and noticed that one is leaking.Update #2: after disposing of all of the liquid-filled blocks, and taking out the others AGAIN, a toddler was able to break one of the sand blocks within minutes of play. Contacting both Guidecraft AND Kaplan proved futile in getting a refund or exchange or anything. Apparently their warranty IS the 30 days that Amazon allows for return. AND now they’re 30% cheaper, so I’m just screwed all around. DO NOT BUY!!!

Perfect for our grandson

Two of the blocks with red dye leaking. Would not recommend.