Measures in intervals of 10 grams (look at the display x.xx KG, .01 of a KG being 10 grams), or in pounds and whole ounces. Auto switch off. Weighing hook swings easily to all directions and can be clipped up the back when not in use. Runs off a 9v battery. Seems very sturdy, though the instructions warn that these scales aren't water-proof or shock-proof; though I'd doubt that dropping them on the river bank or a few seconds of light rain would be a problem, and like all these devices I wouldn't leave them in a damp tackle box unprotected for any length of time.
Diameter is 10 cm, and length from handle top to bottom of extended hook is 20 cm, 15 without hook down. Depth at widest point, around 3.5 cm. The handle is big enough for a grown bloke to get his index, middle and fourth/ring finger in. Not sure how comfy that would be at 25kg, but let's face it, that's not a realistic scenario!
Most importantly, I've tested these against other scales and on objects I know the weight of, and they are accurate. So, nothing to complain about, you could do a lot worse, and depending on how much you pay, I think you'll be happy with them.