Quick overview from the supplier:
Dell Slim Soundbar SB521A for Pro 2 ID Displays
---
Designed For
P-Series Monitors:
P2222H, P2223HC, P2422H, P2422HA, P2422HE, P2423, P2423D, P2423DE, P2721Q, P2722H, P2722HE, P2723D, P2723DE, P2723QE, P3221D, P3222QE, P3223DE, P3223QE, P3421W, P3421WM, P3424WE.
U-Series Monitors:
U2421E, U2422H, U2422HE, U2422HX, U2424H, U2424HE, U2722D, U2722DE, U2722DX, U2723QE, U2723QX, U2724D, U2724DE, U3023E, U3223QE.
