Microscale photochemical reactor with internally threaded connections both top and bottom of head. Top is #15 Ace-Thred that accepts 12.5-14mm O.D. tubes such as 9720-23 Finger Condenser; bottom is #25 Ace-Thred that accepts a 24mm O.D. quartz or glass (borosilicate) tube for photolysis experiments. Complete item consists of head, #15 and #25 Nylon with O-Rings, 9730 Cap Stopper with cap and O-Ring, finger condenser, and either quartz or glass 25x125mm reactor tube.