Here is the sizing table we use. It clearly shows for 5.5” girth you need a 2” diameter cylinder.
Selecting Your Cylinder Size
If you want to calculate it your self, the equation is:
Circumference (girth) = 3.14 x diameter of cylinder
Rearranging to solve for diameter when girth is known:
Cylinder diameter = girth / 3.14
Cylinder diameter = 5.5” / 3.14
Cylinder diameter = 1.75”
The diameter equivalent of your girth is 1.75”. As you have found out, your 5.5” girth packs this tube. You need to go up to the next size tube (2”) to have free space for continued growth.
You may be able to find a 1.875” tube, but you will probably outgrow it quickly.
Initial: 7” BPEL; 6” NBPEL; 5.25” - 5.5” MEG
Current: 7-7/8” BPEL; 7-3/8” NBPEL; 8.5” BPFSL; 6.5” MEG; 6”x5” Flaccid.
Goal: Improved/consistent EQ while managing ED. Secondary: maintain current stats.