Every number we have.
Target specifications for the Relay R1. Some numbers come from the Qualcomm SDX35 reference; others are our own design targets. What's measured is measured, what's a target says target — and every figure firms up as we move through certification.
The whole spec sheet.
| modem | Quectel RG255C-GL · Qualcomm SDX35 |
| standard | 5G NR RedCap · 3GPP Release 17 · sub-6 GHz |
| peak downlink | up to 223 Mbps (theoretical) |
| peak uplink | up to 123 Mbps (theoretical) |
| fallback | LTE Cat 4 — 150 / 50 Mbps (theoretical) |
| US carriers | AT&T + T-Mobile (nationwide 5G SA) · Verizon not supported at launch |
| data interface | USB 2.0 over USB-C (480 Mbps ceiling — never the bottleneck) |
| power | USB-C bus-powered · ≤ 4.5 W peak · no battery |
| dimensions | 70 × 35 × 7 mm |
| weight | ~ 22 g |
| shell | PC/ABS, UL94 V-0 · matte soft-touch · IPX4 is a design target, not a rating |
| SIM | nano-SIM tray · carrier-unlocked |
| macOS | Catalina 10.15 + · native CDC-ECM · zero drivers |
| other OSes | standard USB networking · validation during certification |
| colors | Silver · Space Black |
| price | $199 USD |
theoretical = the RedCap spec-sheet ceiling, not a promise. real-world throughput depends on signal and network load — we publish measured numbers when we have them, not before.
Sub-6 GHz, everywhere it counts.
n1 n2 n3 n5 n7 n8 n12 n13 n14 n18 n20 n25 n26 n28 n30 n38 n40 n41 n48 n66 n70 n71 n77 n78 n79
Nationwide US coverage on AT&T (n5/n77) and T-Mobile (n41/n71) 5G SA — the two US carriers with nationwide 5G Standalone — plus EU/Asia bands. Verizon is not supported at launch.
LTE band chart — verified against shipping hardware, published before launch
Where 5G SA isn't available yet, Relay falls back to LTE Cat 4 — up to 150 Mbps down / 50 Mbps up (theoretical), single carrier. Still more than a video call, a screen share, and a git push need at the same time.
mmWave — n257 n258 n260 n261
A deliberate trade. mmWave needs four extra antennas and a different RF front-end — and RedCap doesn't speak it. On the long-term roadmap, not in R1.
the NR list is the module's datasheet band set. the full carrier-validated band chart — 5G and LTE — is re-verified on shipping hardware and published before launch.
It looks like ethernet. Because it is.
Relay enumerates as a CDC-ECM network adapter — a standard macOS has shipped natively since Catalina, 2019. No driver, no carrier app on the critical path. It works the same way Apple's own USB-C-to-Ethernet adapter works.
And it runs USB 2.0 data over the USB-C connector — deliberately. USB 2.0's 480 Mbps ceiling is more than double RedCap's theoretical peak, so the bus never bottlenecks the radio. USB 2.0 signaling also means lower power draw and zero interference headaches next to the antennas.
$ # plug relay in. then: $ ifconfig en7 en7: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> status: active $ # that's it. there is no step 3.
illustrative — interface names vary by Mac. the point stands: no relay software appears anywhere in this picture.
Mac first. Everything else, validated.
Catalina 10.15 +, native.
CDC-ECM has shipped in macOS since 2019 — zero drivers, day one. An optional menu-bar companion app is on the roadmap for signal and data stats; it will never be required.
Standard USB networking.
Kernel CDC-ECM plus NetworkManager/ModemManager — Relay shows up like any ethernet interface, Pi to workstation. Validated during certification.
Validation before claims.
Windows support is planned via standard USB networking — and we won't claim it until it passes validation during certification. No driver-download treasure hunts; that's the bar.
The wired-ethernet path.
iPadOS treats USB-C ethernet adapters as real wired connections. Expected to work the same way; validated before ship.
Same standard, same story.
ChromeOS speaks standard USB networking too. Expected to work on USB-C Chromebooks; validated before ship.
After the Mac ships.
Modern Android hardware with USB-host support should work — but per-OEM behavior varies, so we won't claim it until we've validated it. Mac hardware ships first; Android follows.
"expected" means CDC-ECM is a standard these systems already speak — not that we've tested your device yet. the tested matrix is published before the product ships.
A dual PIFA array. In 7 mm.
The hardest engineering on Relay isn't the modem — it's making two planar inverted-F antennas coexist inside a 7 mm enclosure without killing each other's isolation.
Everything below is a design target from simulation, not a chamber measurement. We'll publish the measured numbers — good or bad — once validation is done.
Design target
across band pairs — chamber measurements published after validation.
Design target
tuned per band — low bands are the hard part. numbers to follow.
Module: certified. Host: in progress. Nothing ships before the grant.
The Quectel RG255C-GL module inside Relay carries its own FCC certification. Relay's host-device authorizations are what we're working through now — and no unit ships until Relay's own grant is issued.
Authorization in progress.
The module is FCC-certified; host-device certification for Relay itself is underway. We will not ship any unit until Relay's own FCC authorization is granted.
RED 2014/53/EU + EMC + LVD
Notified-body testing targeted for 2027, ahead of shipping. EN 301 908, EN 301 489, EN 62311 (SAR) compliance.
RSS-130 / RSS-247
Filing in parallel with the FCC. Same modular path, same rule: no grant, no shipment.
AT&T + T-Mobile
PTCRB testing targeted for 2027, ahead of shipping. Each US carrier requires separate device approval for full 5G NR access. Verizon is not on the launch roadmap.
every certification date on this page is a target, gated on testing. the ship window — Q2–Q3 2027 — already accounts for that.
Signed updates. For the life of the device.
Every Relay shipped gets free signed firmware updates for as long as we make them — five years guaranteed. Bug fixes, modem revisions, new bands as carriers light them up. Delivered through the optional menu-bar app or a one-line CLI.
$ relayctl update checking relay5g.com/fw … up to date fw 1.0.0 · signature ok (Ed25519) nothing to do.
illustrative — the CLI ships with the device, not before it.
Just email us.
We answer our own mail. No support funnel, no ticket queue — a human replies, usually Kavin.
Reservation only · No charge until shipping · FCC authorization in progress · Ships Q2–Q3 2027