It fits all TVs that have the following VESA holes:
200 x 200 mm, 300 x 200 mm, 300 x 300 mm, 400 x 300 mm, 400 x 400 mm, 600 x 400 mm.

Otherwise, just Google your LG model or look in the manual and check what VESA hole your TV has :)
If neither is available, simply take a metre and measure the distances between the VESA holes at the back of the TV.