This is an ultrafiltrate system for use with 250, 500 and 1000 ml bottles and Millipore filter of 0.45 um and 50 mm diameter. This system can be sterilized with gas, alcohol or ultraviolet light. The idea is to keep the liquid sterile all the time and not have to pass it from a sterile container to the bottle. The design is made to be easily printed and assembled using only epoxy glue. Another extra material is an O-ring of 45 mm in diameter. Instructions for assembly and use are in the "Instructions.pdf" file.