There are even more possible regions in a nuvi device, a total of 254 or 255 from memory. However many aren't populated and therefore copy as empty (0 bytes in the BIN file) and some may not even exist as you've already found with 152. Some may even be duplicates of others. You should exclude regions 48 and 83 because one will contain the entire file system, i.e. at least one of those two will be populated and the other will be either empty or a duplicate. Easier to just do a simple copy/paste of the visible files with hidden and system files shown in windows folder options than to have to convert from 48.bin or 83.bin, also it takes a long time to copy large regions to bin file on SD.