Mini GaussSense is a breadboard-compatible, tileable module for fast-prototyping with arduino and breadboard.
Each set consists of a 2cmx2cm 4x4 Analog Hall-sensor grid (1cm-thick), a breadboard adapter, and a magnet.

Tech Spec of Mini GaussSense: 

• Dimension: 2cm (W) x 2cm (L) x 1cm (H)
• Sixteen Winson WSH136 Analog Hall Sensors
  (Each sensor 600 gauss bipolarly on 5V supplied voltage)
• A breadboard adapter with standard 1”-pitch Dupont Connectors
• A 2cm-diameter cylindrical magnet