This is an addendum to my previous review.
Ravenshead DO state that these are made from "un-tempered glass" and rightly so, as the glasses WILL crack some time down the line with use. The crack can occur at anytime and usually becomes evident as soon as you place the glass on the coffee maker's drip tray, and usually at the bottom where the upright sides of the glass join the thicker base material.
BE WARNED that these glasses are definitely NOT suitable for HOT drinks particularly COFFEE straight out of the coffee machine, unless you FIRST gently pre-warm the glass you are going to use.
I therefore can no longer recommend these glasses for HOT coffee.