The large insert is an optional accessory for the Osbon Erecaid XX50 esteem. The large Slip Bushing/Insert is used to narrow the cylinder chamber to provide a better vacuum seal. Using a Bushing will also increase comfort against the body, rather than using the cylinder alone. Thus, making your return to form on your sex life that much easier and comfortable.
If you are using large insert and still needing to fill space at the base of the cylinder, consider trying the Small Customer Insert
Keep your vacuum pump in top quality and regain your confidence in comfort with the Erecaid Insert large.