This video shows how to measure and repair your damaged electric meter box with a Ritherdon R17 Electric door and frame repair unit.
The fixing method for this repair unit is internal fixing, using fixing plates that screw onto the existing plastic backbox.
Most Ritherdon meter box repair units fix internally just like the R17E - which means that all meter box repair units will be fitted in much the same way as in this video.
The notable exception is only for the front fixing R10 E and G that comes in 6 different size variants. The R10E and R10G are designed to go over the entire damaged meter box. Please note that the R10E and R10G have no cut-outs for pipes, so make sure that this suits the meter box you are repairing.