HIGH QUALITY - This rock polisher grit refill pack comes with enough high-quality silicon carbide grit to put a dazzling polish on up to 9 kg of rocks, gems, glass, and more.

EASY TO USE FOUR-STAGE ROCK GRIT - The first rock tumbling grit stage provides initial shaping, the second smooths rock surfaces, the third pre-polishes rocks, and the fourth provides the final polish.

COMPATIBLE WITH ALL TUMBLERS - This complete 4-step rock tumbler grit refill kit works with all rock tumblers. For best results, use with National Geographic Rock Tumblers and rock tumbling supplies.

EASY TO MEASURE AND STORE - Each rock tumbling grit stage is packaged in a wide-mouth container with secure, screw-top closure.

HIGH-QUALITY EDUCATIONAL TOYS - National Geographic is proud to make the highest quality hands-on science toys, and all our products are backed by exceptional service. If your experience is anything less than extraordinary, let us know so we can make it right for you!