The Dell part number TT15C (or 0TT15C) is an SD 4.0 Card Reader Daughterboard specifically designed for Small Form Factor (SFF) Dell OptiPlex and Precision workstations. It adds a front-facing SD card slot to these desktops. 

Compatible Dell Models (SFF Only)

This card reader is designed for the following SFF (Small Form Factor) systems, supporting 8th to 14th Gen CPUs: 

OptiPlex: 3000 SFF, 3050 SFF, 3060 SFF, 3070 SFF, 5050 SFF, 5060 SFF, 5070 SFF, 5080 SFF, 5090 SFF, 7010 SFF, 7020 SFF, 7040 SFF, 7050 SFF, 7060 SFF, 7070 SFF, 7080 SFF, 7090 SFF, 7000 SFF.

Precision: 3420, 3430, 3431, 3440, 3450, 3460.

Vostro: 3710.

Inspiron: 3020s (Small Form Factor). 

Key Compatibility & Installation Notes

Form Factor Restriction: DO NOT purchase for Micro Form Factor (MFF) or Tower (MT) models. It is designed specifically for SFF.

Driver Requirement: The card reader requires a Realtek Memory Card Reader Driver, which may need to be downloaded from the Dell support website.

Alternative Part Numbers: The TT15C may also be listed under part number K28KG (0K28KG).

Operating System: While it works on Windows, it may not support Linux systems.