What's in the boxOur Vertical Blind Slats are carefully packed with fitting instructions, and optional fixtures and fittings. Please consult our fitting videos for help on how to install your made to measure product. Measuring Slats Only If you have an existing slat, measure from one end of the fabric to the other. This is known as the hem to hem drop or shoulder to shoulder in the trade. Alternatively if you don’t have an existing slat, measure from the bottom of the headrail hook to where you want the fabric to finish.