Many 40 oz insulated tumblers are tapered or labeled "cup-holder friendly" and are designed to fit most car cup holders. Several listings also mention handles or comfortable grips for easier carrying.
Many tumblers advertise leak-resistant or leakproof lids and include locking mechanisms such as push-button locks or dedicated locks. A few straw-tumbler designs claim full leakproof performance when locked.
Review summaries most often praise thermal performance (long cold/ice retention), design and color options, and ease of use or cleaning. Reviewers also frequently note build quality and durability, cup-holder fit and capacity, leak/spill behavior, and overall value.