This is a spike-type head for a throwing spear, made from stainless steel.  Very strong and durable.  This head is safe to use on both hard and soft targets.  To mount this head to a shaft, it is recommended that you get a good shaft made of a hardwood like ash, with a diameter of at least 1"-1.25", and at least 4 or 5 feet in length.  Drill a lengthwise hole into one end of the shaft, at least 2.5" deep.  The diameter of the hole is going to depend on the flexibility of the wood that you choose, you want it to be snug but not too tight.  Mark a spot on the outside of the shaft where the hole is in the head's tang, then insert the tang into the hole and hammer it into place.  Drill a hole crosswise into the side of the shaft, going through the hole in the tang, and secure it in place with a bolt.

Here are the measurements for this item:

overall length: 15 inches (38.4 cm)

blade length: 12.5 inches (32 cm)

tang length: 2.5 inches (6.4 cm)

blade thickness (at base):  0.62 inches (1.6 cm)

tang thickness:  the tang is rectangular, with one side being 0.3 inches (0.77 cm) thick, and the other side being 0.47 inches (1.2 cm) thick.

weight: 8.5 ounces (241 grams)