"SV" models have a dial speed control to control intensity and rotation.    The MT-4 Mini-Sonic vibratory tumbler is a handy, compact version of the larger Mini-Sonic electronic tumblers.  It has the same patented tumbling action, same quiet operation when it is at work safely polishing your stones.  

These Mini-Sonic tumblers will process almost any type of stone - from opal to topaz as well as shells, metals, etc.  Tumble polish baroques, preforms, beads, etc. fast and efficiently without changing the shapes. 

The MT-4 has a large capacity - about 4 pounds load and grit - and is suitable for anyone wanting to tumble stone or metal parts in modest quantities.

These tumblers are top performers when it comes to long life and little maintenance.  They operate without shafts, belts, pulleys, eccentric weights or even a motor - no moving parts to wear out.  Even the hoppers give exceptionally long wear.  They are made of cast polyvinyl, while the tumbler housing is durable ABS plastic.  You will get a tumbler built for years of worry-free service.