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๐ Polish Like a Pro, Rock the Results!
MJR Tumblers' Refill Grit Kit delivers an industry-leading 12,000 grit sub-micron aluminum oxide polish, premeasured for easy 4-stage rock tumbling. Designed for 40lb rotary or vibratory tumblers, this premium kit includes silicon carbide grits and exclusive polish, backed by a disabled and veteran-owned American company with expert instructions for flawless finishing.







| ASIN | B07F6XZGSM |
| Age Range Description | Kid |
| Best Sellers Rank | #13,263 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #9 in Tumbling Media |
| Brand Name | MJR Tumblers |
| Color | Grey |
| Customer Reviews | 4.5 4.5 out of 5 stars (1,237) |
| Educational Objective | Team Building Skills |
| Indoor Outdoor Usage | Indoor |
| Is Assembly Required | No |
| Item Weight | 120 Ounces |
| Manufacturer | MJR Tumblers |
| Manufacturer Minimum Age (MONTHS) | 8.0 |
| Manufacturer Part Number | MJR40pgk |
| Material Type | Extreme Aluminum Oxide, Plastic Pellets, Silicon Carbide |
| Operation Mode | Manual |
| Power Source | Manual |
| Size | for 40lb barrel |
| Supported Battery Types | No batteries required |
| Theme | Geology |
L**E
Works well
Good product
J**E
This is TRUE GRIT!
This is simply some of the best quality tumbler grit I have used. If you do the first three stages properly, then the 12,000 girt polish will be perfect. All in all this is good, works well in each stage, easy to use. the only thing that might make it better would be to package it in bottles instead of bags, but honestly, that's about it.
J**R
fair product
as described
K**R
Skipped a step
I bought this set when I first started tumbling rocks. The grit works well. My only complaint is that I got 2 bags of the step 1 grit, 1 bag of step 3 grit, and 1 bag of step 4. I didn't get any step 2 grit.
K**A
Passion-fueled and high quality
This grit and polish set is exceptional. You can tell it was crafted by people who genuinely care โ not just about rocks, but about the process and purpose. This company emanates expertise and enthusiasm, and that shows in the results. My rocks came out more beautiful than ever and I would prefer to buy only from these rock guys. The picture is of some rocks from my apartment landscaping after the process . The instructions are detailed but easy to follow. Itโs not your typical instruction manual, rather a sincere document created by the seller from the heart (their tips and tricks included!). Itโs really unique and special. Iโve been using a โgimmickyโ tumbler set for my HS STEM program and at home with my kids. As a teacher, is a great tool for many lessons and even many subjects.
T**I
Price is perfect
Thanks for making such an awesome product itโs amazing
B**S
Bags are not full
Only used the 60/90 so far but I got very little grit in each package. This grit does not feel as strong/sharp as what came with my tumbler, coincidentally that is about how much you get in this order, enough for about one tumble like you get with your kit.
B**N
Great product deceptive practices
Absolutely wonderful product but where there is a positive there's also a negative. The way the bags are presentoo.Seem like you are getting a lot of product. Once hung in that bag , it comes to less than a half an inch of product on the bottom. Quit the deception quit wasting plastic and if you're gonna cell that smell of quantity. Please do not deceive the customers with the large bag.Cut it down your size
K**E
I purchased a rock tumbler, the first time I uses it I used the grit it came with. I wasn't happy with results. So looked into different grit. I only used the shine grit ( last stage) on the rocks that had already been tumbled with a shine grit and I was surprised at the difference. I haven't used the others but I'm sure the quality is just as good.
T**N
After 11 days, I received the grit! Polishes rocks nicely!
S**O
fast delivery from the US to the UK arrived with NO leakage of grit. Was confused about the amount as said 50lbs was thinking that was the wieght of it, but after checking more I realised was for a 50lb tumbler size . So was spot on wieghing 9lb. 60z.
A**Y
I'm new to rock tumbling, I've used a few different polishing grits and this is the best one so far. I ran this polish cycle for 7 days and am happy with the results.
L**E
There was loose grit all over the packaging which had to be thrown away and meant the grits were contaminated with other grades of grit so unusable
Trustpilot
1 month ago
4 days ago