These are the magnets we use to manufacture most of our large products (commonly found in the plastic frame of our formicaria). Made of rare earth neodymium material plated with nickel to prevent as much as possible corrosion. 
 
Measure 8mm in diameter by 3mm in height. 
 
Each magnet has an estimated pull of 1800 grams. 
 
These 8x3mm magnets are powerful; please handle them with care. Do not let them snap into place, as the impact can cause the glass to break. Always have a firm grip on each, and do not let them loose, as they will slide onto the nearest magnet or metal surface. 
 
If you are interested in placing a large order, depending on the volume, we may be able to give a discount; let us know what you need by emailing info@poramorart.ca for more details.