ABS is the type of plastic. Typically keys are ABS, PBT, or POM. ABS is easily doubleshot but at the cost of being less durable and easier to shine than PBT. Doubleshot means the key is actually made with separate "shots" of plastic into the mold (in this case white for the letters, or legends, and black for the body of the key). 1.5 mm is the cross sectional girth of the key wall and thicker always better boi