This Thompson/Center Arms Encore ProHunter features a threaded barrel with a hub adapter and is equipped with an EOTech HWS EXPS3. *** The EOTech requires a battery. *** Get the best bang for your buck when you get a Certified Used Firearm. When you see the Certified Used stamp on any of our firearms, you can be confident that you're getting exactly what you want - a gun only in very good to excellent condition and held to the highest quality standard. All Certified Used Guns come with a 'no questions asked' return policy.