20PCS 634ZZ Metal Steel Rolling... https://www.amazon.com/dp/B0816DNF7Z?ref=ppx_pop_mob_ap_share

And

4x12x4mm Miniature Deep Groove... https://www.amazon.com/dp/B00ZHSSC4Q?ref=ppx_pop_mob_ap_share

I have so many extras that I can give to you, but probably easier/faster to buy them on Amazon