The only difference between the TS-81 and the TS-71 above, is the TS-81/WS model is powered by any 12V vehicle battery or 12VDC adapter, which makes it suitable for workshop use.
Whereas the TS-71/ME model includes internal rechargeable 1.5Ah NiMH batteries that provide up to 6 hours of autonomy.
Other than the way each of these models is powered, everything else including accessories is exactly the same.

The industry standard for fast & accurate synchronizing of 4 x carburetor / FI throttle valves on 2 & 4 stroke engines. Suitable for 2 & 4 stroke engines.
Hook up 6 cylinders with the optional adapter kit.

Bright, water resistant & buoyant holder makes it ideal for on-board marine & external use Four vertically arranged LED bars (40 LEDs per bar) provide clear visuals even in sunlight.
Shock resistant composite molded polyurethane & polycarbonate casing is strong & resilient. Self calibrates for barometric pressure changes. Solid state medical grade sensors are drop proof.

Three selectable modes provide the total synchronizing solution:

• ‘RPM’ mode for adjustment of engine speed of 2 or 4 stroke engines during synchronizing.
• ‘AVE’ mode with 3 overlapping scales from 5 to 55 cmHg & fixed resolution of 0.5cmHg for general synchronizing.
• ‘DYN’ mode for troubleshooting - allows for immediate visual check why engine cannot synchronize, possibly causes could be a non sealing valve or a cracked manifold.

Two models are available - The cost effective WS (workshop) model is powered by any 12V vehicle battery or 12VDC adapter and is suitable for workshop use.
The easy to use ME (marine) model includes internal rechargeable 1.5Ah NiMH batteries that provide 6 hours autonomy. Recharge the battery with any 12VDC source, such as a vehicle battery or 12VDC adapter while synchronizing. 
The kit includes soft nylon travel case, battery cord-set, T-connector & 4 x M5 & M6 flexi-rigid manifold connection adapters.  

A 2 year limited warranty is offered. Service centres in USA & Canada.