Square D 9001KA53 Harmony Contact Block Brand: Square D. Part Number: 9001KA53. Schneider Electric Harmony Contact Block, Power Reed, Series: 9001K, 30 mm Size, 1NC Contact Configuration, 3 A, 240 V AC/115 V DC Contact, Silver Alloy Contact, Momentary Action, Power Reed Operator, IP20 Enclosure, Screw Clamp Terminal, Threaded Mounting, Nylon, Clear. Additional Description: SQD -9001KA53 30MM CONTACT BLOCK 1N/C POWER REED. Catalog Description: Contact block with protected terminals, Harmony 9001K, Harmony 9001SK, 240V, screw clamp terminal, power reed, hermetically sealed, 1NC..