From DUDEK Emil: Early bulky basic calculator with archaic functions but sturdily built. The logic is pants with limited decimals, strange 12 digit calculations and numerous bugs. The original black plastic cover is side-bottom-side zip case with Caltronic 812 embossed on the front. The inside is lined with purple felt with Caltronic 812 in framed silver – testament to the high price no doubt. It also has a black plastic, purple felt lines carry strap.