3TK2-1: (Single Position Mounting Track) This plastic mounting track is suitable for mounting a single I/O module to a flat surface. (3 1/2" x 2")

3TK-2: (Dual Position Mounting Track) This plastic mounting track is suitable for mounting two I/O modules to a flat surface. (3 1/2" x 4")

3TK2-2W: (Dual Position Wide Spaced Mounting Track) This plastic mounting track is suitable for mounting two I/O modules to a flat surface with extra wiring space between modules. (3 1/2" x 5")

3TK2-3: (Three Position Mounting Track) This plastic mounting track is suitable for mounting three I/O modules to a flat surface. (3 1/2" x 6")

3TK2-3W: (Three Position Wide Spaced Mounting Track) This plastic mounting track is suitable for mounting three I/O modules to a flat surface with extra wiring space between modules. (3 1/2" x 8")

3TK2-4: (Quad Position Mounting Track) This plastic mounting track is suitable for mounting four I/O modules to a flat surface. (3 1/2" x 8")

3TK2-4W: (Quad Position Wide Spaced Mounting Track) This plastic mounting track is suitable for mounting four I/O modules to a flat surface with extra wiring space between modules. (3 1/2" x 11")

3TK2-6: (Hex Position Mounting Track) This plastic mounting track is suitable for mounting six I/O modules to a flat surface. (3 1/2" x 12")

Note: I/O modules are only depicted for reference and not included with the purchase.