Equisafety Horse in Training Air Waistcoat in Yellow. The Equisafety Air Waistcoat is cut to ergonomically fit the body making it comfortable to wear. The Waistcoat features a quality front zip and is adjustable across the back making it ideal for use during summer or winter as it can be adjusted to accommodate a larger winter riding coat and then reduced in size during the summer when less layers are being worn. The Air Waistcoat features Horse In Training Please Slow Down across that back in bold print and offers two large zipped hidden pockets at the front, which are large enough for car keys, phone and money etc. Sizing: Medium - UK 12-14 (34-36 chest) Large - UK 16-18 (36-38 chest) XLarge - UK 18-20 (38-40 chest)