https://dulytek.com/collections/dulytek-rosin-presses

A rosin press is a machine that uses a pair of heated plates to press with enough pressure any cannabis material, such as buds, keif, or hash, which causes the cannabinoids and terpenes to seep out in an oily form called rosin. Rosin gained popularity with its solventless yet easy extraction process.

What the other user said.

I’m pressing bubble hash into rosin with the intent of decarbing it for e-carts. No solvents needed, but I do have some for more discreet use.