WorkForce ET-3750
The WorkForce ET-3750 is a business EcoTank all-in-one that shipped with two full sets of 502 ink — and it is a WorkForce, not an Expression. Its refill family is 502: 127 mL pigment black (up to 7,500 pages) and 70 mL dye colors (up to 6,000 pages each). Compatible Clever Supplies 502 bottles are below.
| Bottle | Type | Color | Approx. Yield |
|---|---|---|---|
| Epson T502120 (compatible) | Pigment ink bottle, 127 mL | Black | 7,500 pages |
| Epson T502220 (compatible) | Dye ink bottle, 70 mL | Cyan | 6,000 pages |
| Epson T502320 (compatible) | Dye ink bottle, 70 mL | Magenta | 6,000 pages |
| Epson T502420 (compatible) | Dye ink bottle, 70 mL | Yellow | 6,000 pages |
| Epson 502 Set of 4 (compatible) | Full bottle set | Black / Cyan / Magenta / Yellow | 7,500 black, 6,000 per color |
ET-3750 Ink: WorkForce Shelf, 502 Bottles Some retailers file the ET-3750 under "Expression." Epson doesn't — it is a WorkForce ET model, and this page keeps it on the right shelf to prevent mix-ups. The ink itself is the 502 family: T502120 black (127 mL, pigment, up to 7,500 pages) and T502220 / T502320 / T502420 colors (70 mL, dye, up to 6,000 pages each; ISO/IEC 24712 with Epson's methodology).
Offices burn black fastest, so note the family design: the black bottle is nearly twice the volume of a color bottle and carries the highest yield. The 4-bottle set restores a full tank bank; singles keep a single color from holding up a workday.
Not your ink: 522 bottles (ET-2720 / ET-2800 / ET-4800). Different size, different keying, lower black yield.