This is a blade-type head for a throwing spear. This head is safe to use on both hard and soft targets, although when paired with a lighter-weight shaft, the shock of repeated impacts on a hard target may damage the shaft. The blade screws onto the base and is removable, which is convenient for safe transport. The interior of the base is hollow and finely threaded (high threads per inch), and the inner diameter tapers down as it moves towards the tip, roughly following the taper on the outside of the base.
Here are the measurements for this item:
overall length: 10 inches (25.6 cm)
blade length: 6.5 inches (16.65 cm)
base length: 3.5 inches (9 cm)
base outer diameter: 1.1 inches (2.8 cm)
base inner diameter: 0.88 inches (2.25 cm)
weight: 8.5 ounces (241 grams)