This is :bit's GPIO expansion board, which is easy to operate.The expansion board can be directly inserted into the :bit, and the expansion board can be cascaded.Product name: BBC :bit GPIO expansion board kitBBC : Bit GPIO Expansion Board STEM Programming Electronic Education DIY KitSize: 64 x 37 x 12mmMaterial: PCB+Metalcolour: blackPackage Contents:1 x :bit expansion board (B)1 x breadboard (small)8 x 1K resistors8 x 10K resistors4 x red 4 x yellow 4 x buttons1 x adjustable resistor10 x wire male to femaleOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.