This adapter is used when attaching a PL-259 male UHF plug to RG-58 coaxial cables (outside diameters = 0.195").
The internal diameter of the UG175U adapter = 0.209".
"Warning - this product contains chemicals, including Lead [B], known to the State of California to cause cancer or other reproductive harm - For more info go to www.P65Warnings.ca.gov"
www.P65Warnings.ca.gov