The HAYTECH Wireless Probes:

• Robust and durable design enabling convenient handling, easy insertion and firm attachment in hay bales. 
  
• Orange attention-attracting colour for easy detection in hay.Several years of maintenance-free lifetime, extendable with a replaceable battery. 
  
• More probes can be added to the system for covering bigger amount of hay bales.

How many probes are needed? 

The safest plan is to place one in each bale. However, even monitoring a portion of the haystack will increase security compared to manual temperature sampling.