These Ek Archery Siege Carbon 15.5" crossbow arrows are made of a lightweight carbon which results in a low weight of 280 grain (about 18 grams).
The arrowheads are are not unscrew-able. In addition, these Ek Archery Siege Carbon 15.5” crossbow arrows have three feathers, two red and one white, and have a length of 39.4 cm (15.5 inch).