Review on Breadboard Solderless Prototype PCB Board - ALLUS BB-009: 3pcs 400 Pin with 4 Power Rails, Double Sided Tape - Ideal for Raspberry Pi and Arduino Projects by Divine Christmas

They're great for the price. They link together but it would be better if they were sold in a set of 4 so you can put them together in a large square configuration. The only downside is that the plus and minus that run the length of the board appear to be molded as a separate piece and are attached to the other part of the board with double sided tape so there is some flex. It would be better if the entire white part was molded in one piece.