BETCKEY 4x6 Direct Thermal Labels, 1 in Core (250 per roll)
For printers that hold rolls inside on a 1 in core—Zebra's desktop models especially—a 250-label roll is the practical size. BETCKEY documents the 1 in core, gap sensing and a temperature-rated permanent adhesive, but not the outer diameter.
Buy if / skip if
Buy it if
- You have a Zebra ZD421d or ZD220d.
- You want a permanent adhesive with a stated temperature range.
Skip it if
- You use a DYMO or Brother printer.
- You need a published OD to be certain of fit.
Pros and cons
What stands out
- 1 in core stated
- Gap sensing
- Adhesive temperature range published
Drawbacks
- Outer diameter not published
- Brand-level compatibility list
Specifications
From the sources listed at the end of this review. Speeds are manufacturer claims; “not stated” means the maker doesn’t publish it in the documents we read.
| Size | 4 × 6 in (102 × 152 mm) |
|---|---|
| Format | Roll |
| Quantity | 250 labels per roll (packs of 1–20 rolls) |
| Core size | 1 in (25.4 mm) |
| Roll diameter | Not published |
| Material | Direct thermal paper |
| Adhesive | Permanent; rated 14°F–158°F (BETCKEY) |
| Sensing / perforation | Gap; perforated |
| Maker's compatibility statement | Zebra, Rollo, Eltron, Intermec, Datamax, Sato and “most thermal printers with 4 in adjustable width”; also MUNBYN, Phomemo PM-246, POLONO, JADENS |
| Exclusions | Not compatible with DYMO & Brother (standard models) |
Printer compatibility
Confirmed = named by the label or printer maker. Conditional = published specs match but the pairing isn’t named, or an accessory is needed. Unknown is never treated as compatible.
| Printer | Fit with BETCKEY 4x6 rolls (1 in core) |
|---|---|
| Rollo Wireless | ConditionalPrinter feeds from outside, so a roll needs an external holder on a 1 in core; spec match only, not named by the label maker for this model. |
| MUNBYN RW403B | ConditionalPrinter feeds from outside, so a roll needs an external holder on a 1 in core; spec match only, not named by the label maker for this model. |
| Zebra ZD421d | ConditionalInternal roll limit 5 in OD; 1 in core is standard on this printer; label maker does not publish roll OD, so confirm it is 5 in or less. |
| Phomemo 241BT | ConditionalPrinter feeds from outside, so a roll needs an external holder on a 1 in core; spec match only, not named by the label maker for this model. |
| Rollo USB | ConditionalPrinter feeds from outside, so a roll needs an external holder on a 1 in core; spec match only, not named by the label maker for this model. |
| MUNBYN P941U | ConditionalPrinter feeds from outside, so a roll needs an external holder on a 1 in core; spec match only, not named by the label maker for this model. |
| Zebra ZD220d | ConditionalInternal roll limit 5 in OD; 1 in core is standard on this printer; label maker does not publish roll OD, so confirm it is 5 in or less. |
| iDPRT SP410 | ConditionalInternal roll limit 5 in OD; core size not published; label maker does not publish roll OD, so confirm it is 5 in or less. |
| Arkscan 2054A-LAN | ConditionalInternal roll limit 5 in OD; core size not published; label maker does not publish roll OD, so confirm it is 5 in or less. |
| POLONO PL60 | ConditionalInternal roll limit 5 in OD; core size not published; label maker does not publish roll OD, so confirm it is 5 in or less. |
| DYMO LabelWriter 5XL | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| Brother QL-1110NWB | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| Brother QL-1100 | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| Brother QL-800 | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| Brother QL-820NWB | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| DYMO LabelWriter 550 | Not supportedBETCKEY states these labels are not compatible with DYMO & Brother. |
| Phomemo M110 | Not supportedThis printer uses Phomemo M-series rolls; this label is generic direct thermal media. |
Analysis
Outer diameter, estimated
A 250-label 4x6 roll typically runs around 4 in across, under the 5 in limit of Zebra's desktop printers—but this is an estimate, not a BETCKEY spec. If your printer's cover won't close, switch to fanfold.
Compatibility notes and common mistakes
Conditional for Zebra ZD421d/ZD220d (1 in core supported; OD unpublished).
- Buying 3 in core rolls for a desktop printer without an adapter.
Alternatives
Rollo 4x6 Direct Thermal Label Roll (500)
Larger 500-label rolls for external holders.
MUNBYN 4x6 Fanfold Direct Thermal Labels (500)
Fanfold avoids roll-fit questions.
Final recommendation
The label format we'd start with for Zebra desktop printers.
Sources
Read and checked on September 27, 2026. We cite manufacturer documents first; third-party hosts are labeled.
- BETCKEY 4x6 direct thermal shipping labels (BETCKEY, manufacturer product page; checked September 27, 2026)
- ZD421 Tech Specs (PDF) (Zebra Technologies, manufacturer spec sheet; checked September 27, 2026)
- ZD220 4-inch Desktop Printer Spec Sheet (PDF) (Zebra Technologies, manufacturer spec sheet; checked September 27, 2026)