There are a couple of ways to tell. First, when removing your filter from under the sink. If you have to release the filter by pushing a little thumb pad on a coupler from each end, you have the "quick connect" version. Look for the filter with the "tips" on the end. Also on this version, you should see a starburst label on the filter with a number "2" on it. Match it up with the "2" on the outside of the box sitting on the shelf of your retailer.
If you have to unscrew a fitting from each end of your filter when removing it or you have a starburst label with a number "3" on it, you have the "threaded fitting version.