It's a cardigan. It's a blazer. It's both! There's no mistaking the amount of polish it will add to any casual look, like this...

1. J. Crew lace print sweatshirt,
2. Topshop floral studs, 
3. Topshop knit blazer,
4. Simone Rocha metallic clutch,
5. Vince shearling trim ankle boots,
6. Frame Denim jeans,