DonnyFL Air Arms S510 1/2 x 20 Double Male Adapter For airguns needing a double-sided male adapter CNC-machined matte black anodized 6061 T6 aluminum alloy Knurled diamond pattern on sides of adapter and cap Holes through threads for easy installation or removal Hole through side of adapter in case it gets stuck 1/2 x 20 threads .79" (20mm) OD Not compatible with the S510 that comes with Q-tec suppressor Works with standard Air Arms S510 and S510 XS models