Sizing: Insulin Pump Straps are made from velcro-elastic, aka: Velstretch and are very soft and comfortable to wear. Please order one size larger than your measurement to ensure an adjustable fit. Color: Color is CRITICAL to fit, as Medtronic, Animas, and t:slim all have slightly different dimensions. Please choose your appropriate make of Insulin Pump when choosing color. The case/strap is designed with the athlete in mind, as athletic clothing often lack pockets. The pump is held in place with a neoprene pocket and attached to your body via an elastic strap secured by heavy duty velcro. The pump slides in and out effortlessly, so you have access to your pump’s features. We spend $39.95 on an Otterbox for our $600 phones: Shouldn’t our $7,000 Insulin Pumps be protected too? 2 millimeter Neoprene serves double duty in providing insulation, keeping things cool on a warm day and warm on a cool day. This product is made in America with the assistance of a disabled veteran: cases are made-to-order. Please allow 1-2 business days for assembly and shipping.