Master Series Annex Erection Enhancer from XR Brands. Divide and conquer with this devious piece. Insert the penis through the main compartment, then place the testicles through the separator: this T-style divider keeps everything snugly in its place. Made of flexible materials, this erection enhancer stretches to fit over the user and keep them just subdued enough to keep things interesting. Measurements: erection ring has 1.39 inches interior width not stretched. Body safe materials: Thermoplastic Rubber TPR.