Who actually makes them, which models exist, what they block — and the US carrier problem that catches most buyers out.
Qin kosher phones are popular, well made for the money, and the single most common source of buyer's remorse in this category — not because of the filtering, which is solid, but because of which US networks the hardware can actually reach. If you take one thing from this page, take the table two sections down.
The handsets are made by Duoqin, a Chinese manufacturer in Xiaomi's ecosystem-investment chain, which is why you will see them listed as both “Qin” and “Xiaomi Qin”. Duoqin does not sell a kosher phone. What is sold as a Qin kosher phone is a Duoqin handset that a kosher retailer has reflashed with a restricted operating system — so the filtering, the app list, the price and the support all depend on which retailer you buy from, not on Qin.
Prices, specifications and band data below were checked in August 2026 against retailer listings and published teardowns. All of it changes — confirm with your seller before ordering.
This is the question, and the honest answer for the F21 Pro is partly, and not reliably.
The F21 Pro shipped for the Chinese and international markets. Out of the box its modem supports LTE bands B1, B3, B5, B7 and B8 (FDD) plus B38, B40 and B41 (TDD). The bands US networks actually lean on — B2, B4, B12, B13, B17, B66 and B71 — are not in that list. Band 12 and band 71 are the low-frequency bands that carry signal into buildings and across rural areas, which is why the failure mode is not “no service” but “full bars outside, nothing in the basement”.
Those bands can be added by flashing the F30's modem files onto an F21 Pro — a documented community procedure, not a supported one. It voids any warranty, it is not something a typical buyer should attempt, and published reports are clear that real-world signal still varies afterwards.
| Network | Qin F21 Pro (stock) | Qin F30 | The Atom |
|---|---|---|---|
| T-Mobile & its MVNOs Mint, Metro, Ultra, Tello… |
Works in some areas, with coverage gaps | Best supported network | Full support |
| AT&T & its MVNOs Cricket, Consumer Cellular… |
Generally unreliable | Not recommended by retailers | Full support |
| Verizon & its MVNOs Visible, Xfinity, Spectrum… |
Inconsistent even when it connects | Incompatible | Full support |
| Israel | Generally fine — B1/B3/B7/B8 are the Israeli bands | Generally fine | All major Israeli networks |
The restriction is applied at the operating-system level rather than by an app, and retailers state it survives a factory reset. Browsers, app stores, social media, hotspot and video streaming are permanently removed. Qin kosher builds are commonly TAG certified — worth understanding that TAG is a filtering service, and that community certification is a separate thing from it.
On the F30's apps configuration the permitted list typically runs to Waze, Gmail, Uber and Calendar. Notably absent: banking apps are not in the current configurations, which catches out anyone expecting to do more than navigate and email. WhatsApp is not offered either — that is true across this category, ours included.
Configurations are set at provisioning and are awkward to change afterwards, so decide before you order rather than after.
We sell filtered Android phones, so read this as our side of the argument — but every figure in it is checkable.
| The Atom | CAT S22 Flip | Qin F30 | Qin F21 Pro | |
|---|---|---|---|---|
| Price | $300 | $225 | $299.99–$304.99 | Varies by seller |
| US carriers | All of them | GSM or Verizon build | T-Mobile only | T-Mobile, with gaps |
| Works in Israel | Yes | Yes | Yes | Yes |
| Durability rating | IP68 | IP68 + MIL-STD-810H | None published | None published |
| Biometric unlock | Fingerprint + Face ID | — | — | — |
| Banking apps | Yes, on the whitelist | Yes, on the whitelist | Not in current configurations | Depends on the seller |
| Android Auto | Full support | — | Waze | Depends on the seller |
| Size / weight | 96 × 45 × 18 mm, 108 g | 119 × 61 × 23 mm, 224 g | Bar, T9 + touch | 131.7 × 53.5 × 9.5 mm, 100 g |
Not sure what your carrier needs? Look it up here — every US and Israeli carrier, with the build each one requires. Or compare seven kosher phones side by side, Qin F21 Pro included.
Not as sold by the manufacturer. Duoqin builds an ordinary small Android phone; kosher retailers reflash it with a restricted operating system that removes the browser, the app store and social media, and those restrictions are reported to survive a factory reset. So “is a Qin kosher” really means “whose kosher build is on it” — the answer depends entirely on the retailer, and so does whether it meets a given institution's standard.
Duoqin, a Chinese manufacturer within Xiaomi's ecosystem-investment chain — which is why the phones are frequently listed as “Xiaomi Qin” even though Xiaomi does not build them.
On T-Mobile and its MVNOs, usually. On AT&T, unreliably. On Verizon, no. The F21 Pro's stock modem lacks bands 2, 4, 12, 13, 17, 66 and 71, which is most of what US networks depend on for indoor and rural coverage. The F30 is the better-supported variant but retailers still describe it as T-Mobile-first, not recommended on AT&T and incompatible with Verizon.
Only in the version a kosher retailer has flashed. A Qin F21 Pro bought from Amazon or a general importer is a standard Android phone with a browser and Google Play, whatever the listing title suggests. Buy from a kosher seller, and ask which filtering build and which app tier you are getting.
No. WhatsApp carries images, video and status media alongside text, so it is excluded from kosher configurations across this category — Qin builds, FIG, and ours. If WhatsApp is non-negotiable, a filtered plan on an ordinary phone will serve you better than any phone here.
The F30 runs $299.99 for Talk + Text and $304.99 with the filtered app set. F21 Pro pricing varies widely by retailer because each one flashes and supports its own build.