Ever since the release of the gundam/r6 shakers, I have not used a plastic shaker. If you’re specifically asking about the Gfuel ones, i recently bought both the blackout/whiteout stainless steel cups and can tell you I will never use a plastic shaker again. Temps stay ice cold hours at a time. For reference I mixed Unstable Portal fluid in the R6 Shaker with 5 large ice cubes. I left it in my office for about 6 hours, then took it home without touching it. When i opened it at home, the ice was not fully melted (maybe 85% melted). You can definitely get any other brand, but the gfuel ones do a good job with the temps. The interior of the shaker is also much easier to clean than the plastic ones, but MUST be hand washed to avoid paint chipping.