Simpson Strong Tie Fpbm44E Ez Fence Post Mender

How long are these from bottom tip to the top edge?

From the pictures it looks like it needs to be driven about 15 inches in? (28 inches length total, so about 13 inches exposed?)

What are the nails or screws size to use with this? How many do I need to use for one piece? Thanks.

do these install at the left and right of a fence post or at the front and rear (inward) sides?