Donny FL Double Sided 1/2 X 20 Male Adapter 

1/2 x 20 Double Male Adapter / Air Arms S510 / Hatsan Jet 1 & Jet 2 Adapter A21

Features

• Any gun that need a double side male adapter
• One side has knurled cap
• Has through hole in the threads for easy tightening or loosening
• CNC
• Matte Black Anodize
• .79 inches / 20 mm OD
• Great for Air Arms