S Series SL6i is designed for heavy-duty hunting rifles. SL6i sound suppressors are available to the larger hunting calibres from .338 Win Mag up to 375H&H. The S series SL6i suppressors are updated and lightened variants of the earlier SL6 suppressor. Sound suppression 18–22 (1 m left of the muzzle, .9.3×62), 21–22 (shooters ear, .9.3×62).

Manufactured in Finland by Ase Utra OY, the S series SL6 suppressors are manufactured out of 300 series stainless steel and are assembled by welding. S series SL6 suppressors feature a robust construction and they are built for a long service life. The S series SL6 suppressor adds only 126 mm to the length of the weapon, the diameter being 44,5 mm.

S series SL6 suppressors are available with a variety of internal threads to fit directly onto the rifle barrel.