This die is numbered 1 to 6, but it is not made like a standard die. Using the four positions, which pair of opposite faces adds up to 7?

1 is seen with 2, 3, 4 and 5, so 1 is opposite 6. 3 is seen with 1, 2, 6 and 4, so 3 is opposite 5, which leaves 2 opposite 4. Only 1 and 6 total 7; 2 and 4 are opposite but total 6, and 2–5 and 3–4 are not opposite at all.