This is a DIY sight. You must assemble it yourself. You will also need a Rail Attachment Piece to attach this your Nerf blasters.
The M.O.D. or Modified Octagonal Drop Sight is designed to compensate for bullet drop on Nerf guns, which is no easy feat. Nevertheless, it manages to accomplish this task, although how well it does this is quite debatable. Whether you buy this sight for tactical or athestetic advantage, this sight will serve you well and look good doing it!
Make sure you check out my YouTube channel, Nautilus Customs and send commissions and requests to my email, email@example.com.