so you can attach 11 mm red dot sights

Turkish Hatsan has in recent years invested heavily in making PCP air rifles

PTW Champer sleeve

which is relatively low

Lancer Tactical M4 Skin, Geometri SENSOMMER so you can attach 11Lancer Tactical, in collaboration with Airsoft Skin Zone, has made a few really cool skins for primarily Lancer Tactical rifles but will also fit some other models. It is produced in a very thin piece of polymer that sticks together and has been treated to protect against UV and scratches. IMPORTANT: Remember to clean your weapon with rubbing alcohol before installation. Remember to use a heat gun or hair dryer to make it work.