Quick Answer
The BetaFPV Pavo Femto is a 2S 75mm brushless whoop built around the DJI O4 Air Unit, weighing 55g without battery and 84g with a 2S pack. It records 4K/60fps onboard and delivers 1080p digital video to DJI Goggles. The catch: at 84g all-up, it is louder and less nimble indoors than 1S alternatives.
Why a 2S Whoop Exists
The DJI O4 Air Unit weighs about 8g. On a 1S platform like the Meteor75 Pro O4 (37g all-up), that 8g is a significant chunk of the total weight. The O4 Lite can throttle to low-power mode when it overheats, which we documented in our Meteor75 Pro review. BetaFPV's answer: double the voltage. A 2S battery gives the LAVA 1102 motors (14,000KV) enough headroom to carry the O4 without sagging in every turn.
The trade-off is weight. At 84g with a 2S 550mAh LiHV, the Pavo Femto is well over double the Meteor75 Pro's 37g. That extra weight means more momentum, louder props (40mm Gemfans spinning harder), and less precise indoor control. But outdoors on a calm day, the Femto holds its line in light wind that pushes a 1S whoop around.
Full Specs
| Spec | Pavo Femto O4 |
|---|---|
| Wheelbase | 75mm |
| Weight (no battery) | 54.8g |
| Weight (2S 550mAh) | 84.4g |
| Motors | LAVA 1102 14,000KV |
| Props | Gemfan 1611 3-blade (40mm) |
| Flight Controller | F4 2-3S 20A AIO |
| VTX | DJI O4 Air Unit (Lite) |
| Receiver | Serial ELRS 2.4GHz (onboard) |
| Battery Connector | XT30 |
| Firmware | Betaflight 4.5.0 |
| ESC Firmware | Bluejay 0.19 |
| Thrust-to-Weight | 6.75:1 |
| Flight Time (550mAh) | ~4:45 |
Flying the Femto: Indoor vs Outdoor
Indoors, its 84g all-up weight means crashes carry real energy. The smaller 40mm props (the Meteor75 Pro uses 45mm) spin faster to hold altitude, making it noticeably louder than 1S whoops. For living-room cruising, we still reach for the Meteor75 Pro.
Outdoors on a calm day, the Femto comes alive. The 2S power and 6.75:1 thrust-to-weight ratio make it snappy, and the O4's gyro-stabilised footage holds up when BetaFPV's soft-mount system is properly seated. But once wind picks up, the tiny props and 84g mass start fighting each other. This is a calm-conditions park whoop, not a windy-day basher.
Femto vs Meteor75 Pro O4: The Real Decision
This is the question we get most. Both are 75mm BetaFPV whoops with the DJI O4. The Meteor75 Pro O4 runs 1S (37g, 45mm props) while the Pavo Femto runs 2S (84g, 40mm props).
For indoor flight, the Meteor75 Pro wins: lighter, quieter, more precise. For calm outdoor flying, the Femto has more power. If your goal is cinematic 4K, neither O4 Lite platform matches a build with the Pavo20 Pro II running the O4 Pro. The Femto is for pilots who want a pocketable 4K park whoop.
What You Need to Fly
The Femto ships BNF with onboard ELRS 2.4GHz. You need: an ELRS radio (we recommend the RadioMaster Pocket Crush), DJI Goggles 3 or Goggles N3 (see our Goggles 3 vs N3 guide), and 2S XT30 batteries. The LAVA II 2S 580mAh gives the best flight time at about 4:45.
The battery holder is moulded into the frame, so it only fits one battery size. Unlike BetaFPV's BT3.0 connector on smaller whoops, the Femto uses XT30 for wider battery compatibility. See our full range of ready-to-fly drones for alternatives.
The PNP Option and Frame
BetaFPV also sells the Femto as PNP (no VTX or camera) for analog, Walksnail, or HDZero builds. The Pavo Femto frame is available separately. But installing the O4 Lite into this frame is fiddly. We would not recommend the PNP route for O4 specifically. Buy the pre-installed version.
UK Regulations
At 84g all-up, the Femto sits under the 250g sub-category but above the 100g threshold that triggers Operator ID registration for camera drones in the UK. You need an Operator ID from the CAA. See our UK drone laws guide.
FAQ
Q: Do I need DJI Goggles to fly the Pavo Femto?
Yes, the O4 Air Unit requires DJI Goggles 3 or Goggles N3. It does not work with analog, Walksnail, or HDZero goggles. For the PNP version, you choose your own video system.
Q: How long does the battery last?
About 4:45 with the LAVA 2S 550mAh LiHV. The 450mAh pack gives about 3:30. Land when voltage drops to 3.3V per cell under load.
Q: Can I fly the Pavo Femto indoors?
You can, but at 84g it is heavier and louder than 1S whoops. For dedicated indoor flight, we prefer the Meteor75 Pro O4.
Q: Does the DJI O4 overheat in the Femto?
The O4 Lite can throttle to low-power mode when hot. The Femto's 2S power means more airflow through the ducts at speed, but in a hover it can still get warm. Keep moving when possible.