
The TA100 will probably suit you if you are just OP. Automotive technicians may need the TA500. My GTC TA100 antennas, which are about 10 years old, are worn out and the retaining pin has pulled out of its captive section. I looked at the TA500, there is not much difference between the new 100 and 500, 500 can do COP and give burn time. Features I don't need but decided to upgrade. I'm very happy with the life the TA100 has given me, which cost about $100 at the time, which is about $10 a year. The original TA100 had trouble reading Honda (OPE) engines as they (earlier) used a resistor plug. Boots. Honda engines are now made in different countries than they used to be (there was the Philippines and Japan) and if you look at the new engines they are three times cheaper than the 'old' ones and my OLD TA100 doesn't seem to have any problems (see Photo) Pictures of the same test engine run today). So maybe the new boots have less resistance? Today I installed a new GX160 on the rammer, I decided I'll post some photos as well. If you ever have trouble reading, try moving the tester away from the coil area and/or slowly away from the connector wire. I recommend this product. And don't buy it direct from GTC, they will even tell you they sell it cheaper through Revain.

Precision Bike Torque Wrench Set for Mountain & Road Bikes - Pro Bike Tool 1/4-Inch Drive with Allen & Torx Sockets, Extension Bar, Dual Readout, and Storage Box
11 Review

Vgate ICar Pro Bluetooth 3.0 OBD2 Code Reader | Scan Tool For Torque Android To Check Engine Light & Car Faults
19 Review

eTORK 3/8-Inch Drive "Click Style" Electronic Torque Wrench: Precise Torque Control (25-250 In. lbs., 2-20 ft.-lb.)
12 Review

Upgrade Your Car Diagnostics With 16 Pin OBD2 Extension Cable Splitter - Male To Dual Female Y Cable - 50CM
17 Review