The Dell 450-18829 is a 45 W AC adapter for powering a laptop. Its 19.5 V output and three-pin connection identify this specific power supply variant.
The laptop-side plug measures 4.5 mm. Check that the laptop uses this plug and connection format when choosing the adapter; the description does not specify compatibility with particular laptop models.
The C6 power cord is not included, so it must be considered separately when assembling the power connection.