A paper shredder that meets the DIN P-4 safety level is intended to irreversibly destroy personal data, for example by lawyers and notaries. Since the General Data Protection Regulation (AVG/GDPR) went into effect, it's mandatory to destroy documents with at least a DIN P-4 shredder. The DIN class of a shredder indicates how well the paper is destroyed. The higher the number after the 'P', the more strips or shreds your shredder creates. DIN P-4 paper shredders turn an A4 into about 421 shreds, which means they're irreparably destroyed. A P-4 shredder is also called a cross-cut shredder.