Many insulated green cups advertise leakproof or spill‑proof lids. Common features include locking flip lids on kids’ bottles, locking or hideable straw systems, and other leak‑resistant closures. Performance varies by model, so check product descriptions and reviews for real‑world leak tests before buying.
Yes — some insulated green cups include temperature‑control (smart) mugs. The examples noted have built‑in batteries (about 80 minutes of onboard heat) and can run longer when used with a charging coaster, offer app pairing, and allow adjustable temperature settings (examples list about 120–145°F). These are less common than standard insulated tumblers.
Most insulated green cups are stainless steel (often labeled food‑grade 18/8). Some models use ceramic or polycarbonate components for parts of the body or lid, and a few tumblers include a copper‑coated insulation layer.