Neodgynium Magnets 3×0.5mm – Pack of 10 magnets.
NeoDymium magnets (sometimes knon as rare earth magnets) are are used in model construction to allow for ease of transportation or to allow the easy swapping of weapons or upgrades. Simply drill the parts you wish to connect and place the magnets in the holes.
Here is a great guide to help.
Please note: the image is for illustrative purposes, not to scale (so don’t try to measure it!)