Image Item No. Description By  4757  Electric Plate 2 x 4 with Contacts Catalog: Parts: Electric 1  58123c01  Electric Power Functions Receiver Unit with Dark Bluish Gray Bottom Catalog: Parts: Electric 6  58123bc01  Electric Power Functions Receiver Unit with Dark Bluish Gray Bottom and Black V2 Print (Version 2) Catalog: Parts: Electric 13  87662c01  Electric Rechargeable Battery 7.4V - NXT, DC plug Catalog: Parts: Electric 69  64892  Electric Sensor, Color - NXT2 Catalog: Parts: Electric 19  55969  Electric Sensor, Light - NXT Catalog: Parts: Electric 18  55963  Electric Sensor, Sound - NXT Catalog: Parts: Electric 12  53793  Electric Sensor, Touch - NXT Catalog: Parts: Electric 19  53792  Electric Sensor, Ultrasonic - NXT Catalog: Parts: Electric 26