12pce Drain Rod Set. The Lock Rod Drain Rod System (patent pending) comprises robust, durable and flexible polypropylene rods with superior interlocking fittings. Double worm screw breaks up obstructions and the plunger creates pressure build-up, forcing obstructions clear. The rods can be rotated in either direction and will remain securely attached. Knurled screw connectors provide an enhanced grip and tool-free connection. Includes 10 x 920mm interlocking rods, 1 x 100mm rubber plunger, and 1 x 50mm double worm screw.