Yes you do need to run a booster with the tekin rs pro.
The turnigy one doesn't fit inline with the servo, though the connectors suggest it does.
The plug on the turnigy one goes into your receiver. I made a servo lead up with just red and black cables soldered to the +/-ve terminals of the speedo, which plugs into the booster. This allows quick removal, but keeps it neat.
It works, but not great. I found i needed to also run a capacitor in the receiver also to stop servo brownouts.
I don't run it any more as i got another speedo with a built in booster, however I did like the Tekin in 1S GT12. With an RC dynamics booster its excellent.
__________________
-------------------------------------------------------------------------------------------------------------------
Team Yokomo - YZ-2CAL3 | YZ-2DTM3 | YZ-4SF2 | YZ-2T | YZ-2DTM Worlds | YZ-2DTM x2 | YRX-12 x2
-------------------------------------------------------------------------------------------------------------------
10electric | Batley Buggy Club | YORCC | RHR | MB Models
--------------------------------------------------------------------------------------------------------------- |