Is modified to pure sine wave possible ???

[snipersquad100]

Hello Peeps
I'm looking for a cheap way to change a modified sine wave from my inverter  to a pure sine wave to run a fridge freezer in my garage.
I found this on ebay 172120985728 but not sure if it's what i need as the English is not to clear.

1000W Pure Sine Wave Inverter Power Board Modified Sine Wave Post Amplifier DIY
Description
Features:
NOTE : IT IS DIY KIT , not assembled
Product Name: Correction pure sine wave inverter stage plate change
Input voltage: DC380V.
Input voltage: AC16V.
Output voltage: AC220V.
Output frequency: 50 / 60HZ "adjustable."
Output waveform: pure sine wave.
1000W use the power tube: 4 / 20N60
PCB Specifications: 200X85X50MM.
Instructions:
The product is a modified sine wave inverter modified sine wave inverters, modified sine wave inverter can 1000W / 2000W / 3000W etc ......, change pure sine wave inverter. After the first correction wave inverter stage power tube removed do not, then take a look at a few amendments wave transformer transformer, look at the transformer secondary circuit is a parallel or in series, again plus transformer parameters, modified sine wave transformer secondary is parallel In each of the transformer secondary plus 16 laps. Modified sine wave transformer secondary is a tandem type, in each transformer secondary plus eight laps. Then add the correction wave transformer where a foot of a small voltage transformer empty parameter, this small voltage parameters using a single copper wire 0.6, in which the transformer winding: 5 laps, this small voltage is link AC: 16V position. (Note: Do not open the magnetic transformer plus parameters) transformer parameters After addition, must take modified sine wave inverter voltage capacitors exchange 220UF / 450V, "Remember: modified sine wave inverter high voltage capacitor positive terminal has a feedback resistance, the resistance of a few hundred K, but also for large point of resistance, not voltage does not rise. "Re-energized test voltage capacitors (positive / negative) voltage is DC380V, after the test voltage is normal, use the link line to the plate after the sine wave level, after level panel output voltage: AC220V / 50HZ, output waveform: pure sine wave.
Package Included:
1pcs 1000W Pure Sine Wave Inverter Power Board Modified Sine Wave Post Amplifier Kits


Does anyone know if this will do the job or have any other idea's
Thank you.