Hatch Model Reverse light bulb size

Hey all! First post here. I have a slight concern about my 18 Hatch tail light. I bought from Wal-Mart the 921 led bulbs to replace my stock reverse bulbs. Upon installation the current bulb base is wider then expected. On the stock reverse bulb it reads; W2W Ew 3KG M 27K13. Curious as to what bulb would i need for replacement? Also I've noticed there are two sockets one on the trunk tail light and the other on the side tail light, I've tried turning and turning but no luck. My goal for the Hatch is to have all bulbs LED. I have photo of the bulb taken from the dome light on the left, the right one is the stock reverse bulb. The LED bulb I bought from Wal-Mart has the same size base as the one on the left.