Developers get a PS3 Test unit (Debugging Station) that allows it to run unsigned code. The machine is normally labelled Test below the PlayStation 3 logo, and it comes with a testkit. The PS3 model numbers for these Test machines are similar to the the ones for consumers, but instead of the CECH prefix, the model numbers have the DECH prefix. Unlike consumer units, a PS3 Test unit has an extra "Settings"->"Debug Settings" menu in the XMB (XrossMediaBar), which allows many options like downgrading to previous PS3 Test firmwares (available in PS3 Test firmware 2.00 and higher), changing the PS3 region, and treating a USB drive as a Blu-ray drive,. The PS3 Test unit is identical to the consumer PS3 unit hardware-wise, but the different software settings is tailored for allowing easy debugging of programs. By default it is missing Blu-ray movie decryption keys found in the retail PS3, but has decryption keys for running debug encrypted software. The PS3 Test, therefore, cannot decrypt and play retail Blu-ray movie discs, but can run retail PS3 games. In the DECHA models, PS2 games (any region, debug and retail) loading were disabled, but later firmwares allow it.