CD 534: Chamber Tops and Gully Tops for Road Drainage and Services, now at version 0.2.0. is here Find out more A QUALITY ABOVE THE REST Unite gully grates Unite gully grates combine new technology with proven features to deliver super long-life and a lower whole-life cost of any gully grate available. View products Load classifications D400 Products suitable for road carriageways, hard shoulders and parking areas.