I found this quoted on another forum, it looks as if it is a 'switch rod'. In a GLX it appears you have a great rod there.
I have a GLoomis
GLX FR 1388/9-3 11'6" rod for sale. I bought it new and it's in excellent condition - cork is a bit colored. Used for three weeks of steelheading in Northern BC. Moved onto different rods now and this one is too good to be sitting around. This is an 8/9wt switch rod that has tons of backbone and is capable of some very long casts. I've used an 8wt dry line on it or a 5/6wt Short Delta."