The Wooden Hamburger is a non-sequential educational stack toy that delights kids of all ages, from 1 yr to 101+. Hand/eye color coordination, finger dexterity, and non-sequential stacking capability, can all be measured with our stacking wooden Hamburger. There's no right or wrong way to stack it. Made of rugged Western Ponderosa White Pine. The colors are non-toxic stain-like impregnated finishes. Launch date: September 1980.