Product review (4 stars): For ERP410 from Exact Replacement Parts, St. Charles IL, UPC: 840993000010
This review is for the received ERP410 from Exact Replacement Parts, 1855 Wallace Ave
St. Charles IL 60174 (url: er.parts) and not the RCO410 from Sealed Unit Parts Co. Inc., 2230 Landmark Pl, Manasquan, NJ.
ERP410
This is about  6.3" X 2.1" and the leads are about 9" so make sure you have space and a plan.
Looks and works exactly like the RCO410 that was ordered. Maybe it's out of the same factory in China? The key difference is that this ERP410  is not UL recognized, where the SUPCO device is: MINUS a Star.

This is just a high-current over-load switch + PTC thermistor + Capacitor. There is no provision for motor temperature detection. Though this does have an overload switch it is likely much larger than what the compressors designers envisaged. For those reasons don't give up your existing overload/Thermal protector.
Nerdy stuff: Usually the failure of the both factory and these are from contacts in the PTC failing, resulting in non-uniform thermal stresses which fracture the barium titanate disk. Once that happens, the motor won't start and the thermal over-load switch cycles, heating the motor and thawing the food just a bit faster than if it were unplugged.

Hint 1: You can get an idea if your compressor is cooked by checking the coil resistances (see Youtube), and the resistance to the case (ground) should be infinity. If you have an insulation-resistance tester, even better.
Hint 2: Sometimes it's possible to disassemble the broken PTC, clean and tension the contacts and reassemble with the largest piece of disk so you have some time: This can last hours or days---or not at all.
Hint 3: Since these devices cannot sense the compressor's temperature and has a trip current that's probably much greater than the design intent of your compressor, it's best to connect this devices COMMON wire to your existing overload switch, which stays on the compressor. In my case I needed to crimp a 1/4" on to the COMMON lead of the device.

Like Supco, the wire that most workers would consider the input-side NEUTRAL is black, just like LINE. Easy enough to sort with an ohmmeter, if you are the fastidious sort. NEUTRAL is the side that has continuity with RUN.
  Terminals are well crimped and they used 105 C, 600 V rated AWM wire. Though they hold to the compressor pins well, I prefer to add a couple layers of 105 C rated electrical tape over them, just in case. It comes with wire nuts for line and neutral and, since there may be some vibration, I prefer to tape over these too. There is a mounting tab suitable for a small Ty-Rap or a #4 or #5 screw but it can be easily drilled with a 9/64 bit for a #6 screw.