This is a 4 ounce (=1/4 lb = 113 grams) ingot cast from Field’s metal, a low-melting fusible alloy made from 51% Indium, 32.5% Bismuth and 16.5% Tin. It melts at 144 Fahrenheit (62 Celsius) so you can melt this in hot water at home and pour it into any mold you can think of (including Legos as shown in the picture!), and because all three metals are non-toxic it’s safe to handle at home. It’s fascinating to melt this in a cup just with hot water, then pour it out and watch it solidify. Besides home hobby use, it can also be used for industrial applications including die prototyping and electroforming mandrels. Legos not included!