FROM WIKI:
Maltesers are a confectionery product manufactured by Mars, Incorporated. Maltesers consist of a roughly spherical malt honeycomb-like structured centre, surrounded by milk chocolate. Maltesers are sold in a variety of packaging, including plastic bags (ranging in size from small 'fun-size' upwards), larger cardboard boxes and tubes, and plastic buckets (ranging in size from medium to very large). They also have medium-sized "teasers" in Celebrations boxes. Maltesers are also one of the types of sweet included in Mars's Revels assortment.
Yes, they are British.