This VGP-BPS12 SONY Laptop Battery can replace the following part numbers:

SONY

VGP-BPL12 battery
VGP-BPS12 battery

This VGP-BPS12 SONY Laptop Battery is also compatible with the following models:

SONY

VGN-Z21ZN/X
VGN-Z31VN/X
VGN-Z31WN/B
VGN-Z51WG/B
VGN-Z51XG/B