The first three figures (Hum 239/A, 239/B, and 239/C) have traditionally been sold as a set and were known as "Children Trio" ever since they were placed into production in the later 1960's. They are essentially the same as the Hum 115, 116, and 117, except that the tree Hum 239 pieces have no receptacle for holidng a candle. In 1997, the trio was expanded with a fourth figure, "Girl With Fir Tree" (Hum 239/D). Also in 1997, a set of four ormanents was introduced. They are designated with a "/0" after the regular Hum number. The ornaments are the same as the Hum 239 figures, except they have brass ring hangers on top instead of bases on the bottom.