This sunbird is 14 cm long and exhibits a clear sexual dimorphism.

The adult male has a glossy, metallic green head, throat upper breast and back.

The male can be distinguished from the similar lesser double-collared sunbird by the latter's smaller size, narrower red chest band and shorter bill.

The closed oval nest is constructed from grass, lichen and other plant material, bound together with spider webs.

It lives mainly on nectar from flowers, but takes some fruit, and, especially when feeding young, insects and spiders.