Our 40x monocular is built for a wider view than most in this power range - 1600m at 9800m out, so a moving bird or a distant ridgeline doesn't slip out of frame every time you shift angle. Its BAK4 roof prism and 60mm objective lens keep the image bright at dusk and dawn, and the nitrogen-filled body is sealed against fog and moisture. 350g, pocket-sized at 144mm.
Hand it to your kid the second something moves on the far ridge, and the wide field keeps it in frame long enough for them to actually find it - that's the difference between a story about a bird you saw and one everyone in the group actually saw.