I picked up the Insulation Sleeve to go with my TMB ModularBottle setup and it does the job. It slides on easily and keeps my drink at temperature noticeably longer during commutes and hikes. The material feels durable and it hasn't picked up scratches. It does add a bit of bulk, so it fits my larger bag better than a cup holder, but that's a minor trade-off. If you want to keep cold drinks cold on long days out, this is a sensible add-on.