These are holsters and belt accessories for the new sidearms for Black Widow in Infinity War. The actual weapon props are also in my library and one is shown in the holster in the main photo.
If you like my 3D models and you are coming to Dragon Con 2018, I'm always happy to discuss the models I have made or anything related. It's also a chance for you to see in real life the version I have built.
The swivel buckle shown in the photo is a bought item and is not included in this kit. You can purchase a Swivi Lockster buckle online or use a similar substitute.
The strap is meant to be printed in a flexible filament. You could also craft one out of more traditional materials.
Strap widths are 38mm (1.5") and 20mm. I recommend using somewhat elastic, but strong strap material. The left and right holsters have 1 or 2 narrow straps around the leg respectively. The 38mm wide slots include modeled break-away support material that should be easy to remove with narrow tip pliers.
The design is loose enough on the prop weapon to allow some lining to be added. I used two round felt stickers inside the holster.