Double-walled, quartz Immersion Well for use with 7825-30, -32, -34, and -36 lamps. With inlet and outlet tubes for cooling or modified with a 4.8mm I.D. PTFE tube attached to a glass tube and secured with a #7 Ace-Thred bushing. Inlet tube extends down the annular space to insure flow of coolant from bottom of well upward to outlet. Well has 60/40 inner joint. O.D. of outer jacket is 53 mm max. Length above joint, 76mm.