Waistcoat by Heart Dagger, Ceremony, speeches and cake-cutting appropriate, Button placket, Contrast back with an adjustable cinch, Slim fit - a narrow cut that that sits close to the body, Exclusive to ASOS. Heart Dagger welcomes ASOS to The House of Heart Dagger with an exclusive tailoring collection. A House which has been built on the very foundations that it strives to uphold and take forward: timeless style, rich fabrics, precision-cut suits and a touch of modern-day dandy.