Plus, the Simax glass bundt pan is made of borosilicate glass and can withstand temps up to 932 degrees F, whereas tempered glass can go to 425 degrees. (eatgood4life.com)
Cons: contrary to Avent bottles these are not made of borosilicate glass, therefore avoid sudden temperature changes (these bottles can not be transferred from freezer onto the bottle warmer). (babygearhub.net)
They are made from borosilicate glass which makes them resistant to thermal shock (you can safely transfer them from freezer to a bottle warmer without a risk of breakage). (babygearhub.net)