Better than glass: it doesn't break and doesn't splinter (no real glass, no tempered glass). This plastic bullet-proof glass has 9H hardness (300g) and an anti-shock coating (shock-absorbing bullet-proof foil). It comes with a 10-year manufacturer's guarantee and is a branded product made in Germany. It is crystal clear (almost unseeable), approximately 0.2mm thin, and features an oil and grease-proof anti-fingerprint coating. It fits perfectly on a 42 mm diameter watch, is bubble-free, and can be removed at any time without leaving residue (without adhesive).