Insert light fields for suspended ceiling systems with visible T-profile module (1250 x 625), homogeneous luminous surface, no UV and heat radiation, tool-free installation, high ease of maintenance, white luminaire housing made of sheet steel, external placement of the control gear on the luminaire body, luminaire ready to plug in to the control gear, operation with or without DALI function possible, microprism diffuser made of clear acrylic glass, control gear (LED converter) included (with DALI dimming)