See how many kilograms you want to salvage. This is made of rare earth, so the price on the market is relatively high. Generally, 85*65*20 (the size of cigarette case is similar) can absorb 3-40 kilograms of fishing magnets. 300 yuan is a little bigger around, 80*80*40 is near 1 thousand. But this magnetic force also absorbs 2-300 kilograms. If you don't know the method, it is difficult to cut off the peak magnetic matter. You can customize it according to your own requirements. You can go to them.