they look like granite to,me so …
The most common things we have seen used include stainless steel forks/butter knives etc or stainless steel racks (to separate food pouches if you are using more than one). Another option is an upside down steamer basket. The perforations in it allow for good water circulation in your water bath.
Actually a simple solution would be to use a gravity retraction device coupled to an inertial dampening system. Once the systems are properly activated you can turn the cooking medium (ie hot water) upside down and the target variable (ie the food) will be trapped in the resultant matrix.
Of course! And the added advantage would be that the fusion reactor used to power the device would be nice and hot - all ready to sear the result of the cook once done!
After many experiments, I now use binder clips, 1-1/4" with 5/8" capacity, and a heavy flatware knife with the bag folded over the knife and then secured with the binder clip. I no longer put weights inside the bag because of having to clean off stuck-on food. Having the weight outside the bag keeps the weight clean. Anything that fits in the 5/8" binder’s jaw can be used. The weight can be snugged up close to the food or at any distance depending on amount of bag available. I have also had success putting the bag in an Ikea rack with the weight on top for maximum immersion of tall items.
Simple, straightforward, and effective! I like it!