TFR8S replaces the TFR8. The 8S can work with the transmitters failsafe. Of couse you can still program the failsafe into the reciever if you prefer.TFR8S FASST Compatible 2.4ghz Receiver compatible with all Futaba FASST transmitter systems for air and ground  R/C applications and can be doubled up with another TF receiver for expanding to 8 channels 

Features:

• Compatible with FASST 2.4G: Air Systems (7CH Mode/Multi Mode) & Surface Systems (C1 Mode).
• Parallel with TFR8/TFR8-S to became a 14 channel FASST compatiable receiver.
• Two selectable failsafe setting options.
• Improved capability of anti-interference.
• Firmware upgradable

Specifications:

• Number of Channels: 8
• Dimension: 54 x 30 x 15mm
• Weight: 13.5g
• Operating VoltageRange: 3.5V~10V
• Operating TemperatureRange: -10°C~60°C

Compatibility: 

• FASST 2.4G Air Systems (7CH Mode/Multi Mode): 6EX, 7C, TM-7, TM-8, T8FG, T10C, TM-10, T10CG, T12Z, T12FG, TM-14, T14MZ, etc.

What's in the Box:

• 1 x TFR8S
• 2x Short tool
• 1 x Manual