These introducer devices are for use with SooJi Chim Handle Needles (see DBC Sooji Chim needles on pg. 26). Each measures 3.5” long and features magnets on the inner tube and top head to pick up the small sooji chim needles.  The Gravity-Type introducer uses the weight of the plunger for insertion while the Spring-Type utilizes an inner spring with depth adjustment knob for insertion.