Features 1. Rock Crusher With our rock/glass crusher, you can easily crush rocks and glass to any size and even pulverize them to powder if desired. 2. To Crush No electric or battery needed. Simply stand on the base plate, lift the plunger and demolish whatever you have in the cylinder. 3. Premium Design This unit is very portable and can be used as a rock or stone crusher for gold prospecting and treasure hunting or as a frit maker for lampworking and glass fusing. .