I handmade a shoulder strap for a Thermos vacuum insulated baby straw mug (model number FJL-350). I am selling them in blue, pink, yellow, brown, ivory, beige, and gray. Please take a look at my profile (some colors may be sold out; I can make them to order if you request a color). *Strap only, mug bottle not included. When you have a lot of luggage with children, a shoulder strap for a straw mug is very convenient for carrying. While the official Thermos cover cannot be used as a shoulder strap, this product allows both children and adults to use it as a shoulder strap by adjusting the length of the belt. Attaching and detaching is very easy, just use Velcro and pass the D-ring through the handle. I didn't want to cover the non-slip bottom, so I made the belt only for the upper part instead of a full cover. My grandchild requested that they be able to carry it from the nursery school, and after much trial and error, I completed it. I use it very conveniently every day. 【Important】Please use it safely, taking sufficient care to ensure that the belt does not tighten around the child's neck.