I ordered two 350ml Lifefactory bottles within the past 12 months for my children. The seal of the first cap worked perfectly and was easily able to draw water up the straw to the spout. The seal of the second cap did not work, drawing only air into the spout rendering the water bottle useless. Upon receipt of the defective water bottle, I emailed a customer service representative from well.ca who sent a replacement water bottle and straw cap without hesitation – which was greatly appreciated! What is frustrating though is that over time the straw cap gets finicky and then eventually loses its seal – as now both of my straw caps do not work and cannot draw water up the straw to the spout. Now I have two useless water bottles. The glass Lifefactory bottle with the silicone sleeve is durable, washes easily and rates a 4.5/5. I have recommended this product several times, especially through well.ca, however the straw cap only gets a 1/5 from this disappointed mom.