Lovebirds are 13 to 17 cm (5 to 7 in) in length, up to 24 cm in wingspan with 9 cm for a single wing and 40 to 60 g (1 1⁄2 to 2 oz) in weight. They are among the smallest parrots, characterised by a stocky build, a short blunt tail, and a relatively large, sharp beak. Wildtype lovebirds are mostly green with a variety of colours on their upper body, depending on the species. The Fischer's lovebird, black-cheeked lovebird, and the masked lovebird have a prominent white ring around their eyes. Many colour mutant varieties have been produced by selective breeding of the species that are popular in aviculture.