The economical T6 Rainbow by MagicYoYo. This unresponsive yo-yo uses yellow silicone pads for response (I know... response pads for an unresponsive yo-yo. Go figure), a concave size C bearing, an M4 x10 mm axle, and body halves made out of 6061 aluminum.
Original retail price: $20 US
To see all mini yo-yos in this museum, in the left panel, click Exhibits.
In the right pane, in the Name/Model field, type mini, then click Browse.