Block 4x4. I haveshot broadheads, field points, & expandables into it. It just keeps going. I made the mistake of buying a morel broadhead target for a friends birthday present and having it shipped to him. I didn't know you shoulden't shoot fieldpoints into it. [:@]He wasn't happy with me as he had to get his wife out to stand on the target so he could get his 8 arrows out.