Range of control units and pilot lights for 22.3 mm mounting diameter. – They are so flat they can be used as a good alternative for membrane keyboards. The external shape of the front bezel underlines the flat design which combines elements of circle and square. The mature detail design supports the formal originality of this product line. RONTRON-Q-JUWEL is a versatile modular system providing umpteen combination possibilities in many fields of application.