I recently ord'd a couple of the SPEWS. I initially used the included belt clip that comes with the knife and sheath, but decided I didn't like it. I then ord'd a couple of the Blade Tech devices. You can attach a knife sheath to it horizontally or vertically, and can be used on belts or on Molle webbing. Lots of imitations out there, so ensure you get the legitimate Blade Tech brand. Link:
Amazon.com: Blade-Tech The Original Tek-Lok Belt Attachment/Clip for Holsters, Mag Pouches, Knife Sheaths and More, Made in USA: Sports & Outdoors
www.amazon.com
I had the SPEW attached vertically to a Blade Tech device, and had it on a bag for fishing, but have since changed it to a horizontal position.
View attachment 10468
The screws (Chicago Screws) that come with the sheaths are usually too short, so I ord'd a pack that has longer Chicago Screws:
Amazon.com : Black Chicago Screws, 12 Sets - for DIY Kydex and Leather Gun Holsters/Clips and Knife Sheaths, 1/4 Inch, Includes Phillips Truss Heads + Open Slotted Fasteners + Rubber Washers/Spacers : Sports & Outdoors
www.amazon.com
Oh, all holes on a sheath may not/won't mate-up to holes in the Blade Tech, so I drilled a hole (bottom left screw in sheath) as seen in the pic of the knife on the bag above, to ensure a more secure mounting.
Amazon.com : Black Chicago Screws, 12 Sets - for DIY Kydex and Leather Gun Holsters/Clips and Knife Sheaths, 1/4 Inch, Includes Phillips Truss Heads + Open Slotted Fasteners + Rubber Washers/Spacers : Sports & Outdoors
www.amazon.com
A touch of Loc-Tite (the Blue stuff) on the screw threads will help ensure they don't come loose and become unscrewed.