This is dual color 'Strap-On" logo V2 adaption of the Snap-On MAGBOWL. I have a V1(Here), V2(Here), and a Strap-On V2. The V1 and V2s use 40mm x 10mm x 5mm magnets. Available from amazon here. Each tray uses 4 magnets and holds very well to whatever you stick it on. I use them daily in a shop environment for lug nuts and studs. They can be printed out of any material you like, I print them out of PLA plus/pro and PETG, they hold up great. Use my included printing profiles for best results.