FITMENT: This rock crusher is very portable and can be used as a rock or stone crusher for gold prospecting/ gold mining trips and treasure hunting or as a frit maker for lampworking and glass fusing, glass decor classes/sessions and more. FEATURES: 1）FUNCTION-- With our rock/glass crusher, you can easily crush broken glass/rock into any size and even pulverize them to powder if desired. 2）EASIER WORK-- No electric or battery needed. Simply lift the plunger and demolish rock, stone, glass, gold and so on in the cylinder. Crush away!! .