Long Sleeved Knit Rib Midi Dress. Looking for something warm, snug and fashionable this winter season? Check out this black long-sleeved rib knit midi dress from Monki. This loose-fitting mid length black dress comes with short sleeves and is a new arrival at Monki. Its mock neck compliments rib knit design making perfect styling for this season. The added bonus is that it is made using recycled polyester. Add boyfriend jeans and boots and WOW!