Rectifier / Controller changes the AC into DC. If the battery no longer charges properly, the rectifier may be the cause. This item matches the original in design and performance and can also be used as a cost-effective replacement. Suitable for Vespa PK 50, PX 80, PK 125, P 200, PX 200, Cosa, XL2 scooters. OEM number for reference 2520255 252025