Tempered glass is physically and thermally tougher than regular glass, and it shatters into small cubes rather than shards, which means there's a lesser chance for you to get hurt if you break it. However, it has the tendency to shatter completely upon hard impact.

Borosilicate glass is a type of glass that consists mainly of silica (SiO2) and boron trioxide (B2O3), which makes the glass more resistant to drastic temperature changes and high resistance to corrosion by chemicals. Borosilicate glass is popularly used in the production of scientific instruments such as laboratory glassware because it can handle both extreme cold and heat. It used to be the choice of glass for kitchenware as well. However, many U.S. kitchenware manufacturers have switched to use soda-lime glass because it less costly than borosilicate glass; for example, glass bakewares manufactured by Pyrex and Anchor Hocking. If borosilicate glass undergoes an abrupt and severe temperature change or falls on a hard surface, it might still crack (but it takes quite some effort to break it). If it cracks, it's in chunks instead of shards, which is much safer than soda-lime glass. The nowaday Pyrex glass breaks into shards.

I don't think you have to worry about the plug being tempered glass and not borosilicate glass, as long as you're careful with the plug — don't drop or bang it against a hard surface.

I haven't tried the Onyx Glass Prostate Massager and I'm female, but I can assure you that this toy won't be comfortable for extended wear since the circular handle is a whopping TWO inches wide! less