capndan771 wrote:
I have the older standard model. The drawback is that batteries cannot be accessed to replace them. It requires sending a sensor back to TST for refurbishing at a cost of $19.95 per sensor. I believe the flow through allows you to replace the batteries which I would imagine is less costly. I have used my sensors for 5 years with no complaints.
Actually, there are 3 TST systems.
1. The 510 with batteries that could not be replaced by the user.
2. The 507 with batteries that can be replaced by the user.
3. The 507 Flow Thru with batteries that can be replaced by the user.