Introduced with the range refresh in 2010 and still in use well over a decade later. Technically they are called "Type B Lugs" or "In‑Line Locking B‑Lugs" (depending on which Mapex documentation you read) but that's not particularly helpful. Mapex did say they were a "new sculpted shape" when they first came out so I've used the term "Sculpted Shield" throughout the database. I didn't invent that term; I saw it used somewhere else and nicked it. Also, I'm not sure exactly why they are even called "B" Lugs. I thought it might be the series, as in "A" series (Oval) "B series (Shield) but the "I" Lugs came out at the same time. If I find out I'll update this page. 

On some shells lke the Metallion and Nucleus, these are arranged in a staggered formation, but they are physically the same lugs so I haven't listed those separately. My first thought was that this was simply stylistic choice as there are other 5.5" deep models with inline B-Lugs, like the 2015 Warbird, the Blade, the Brass Cat and the Stinger. However, after asking around on the Facebook Group, it was pointed out to me that this can give the shell a broader tuning range, as the lug bolts can be longer. Also they have more room to tighten into the lug box than is possible with the later Double-Ended B-Lugs. See - you learn something new every day!