This is the NEWER style which has a slot for the c-clip on the dog post. It is part of a design change made by Penn, so check your housing to see if you are replacing the older (1-5500) or newer housing.
IDENTIFYING OLD/NEW HOUSING
A newer housing can also be identified by the post that the crosswind gear sits on.
On the Older housing 1-5500, the post for the crosswind gear is a straight up/down peg.
On the Newer housings 1N-5500 or 1P-5500, the post for the crosswind gear is cone shaped, wider at the bottom.
IMPORTANT:
If what you currently have is the older housing, there are several other parts that will need to be changed in order to use the newer housing.
See "About 5500ss Anti-Reverse Design Change" link below for more info.