Gerber Answer XL 31-000581 Published April 3, 2013 at 600 × 500 in Gerber Answer XL – A Large Assisted Opening Knife 31-000581 Gerber Answer XL 31-000581 Continue reading → The Gerber Answer XL 31-000581 has a 4 inch blade. The knife is just over 9 inches long when open.