Q: What does '7-pin small round' actually mean?
A: It's the older Australian 7-pin trailer connector pattern, seven brass pins in a small round plastic plug about 32mm across. The newer flat 7-pin connector replaced it from the 1990s onwards, so you'll find small round on older caravans and trailers while most tow vehicles built in the last two decades run the flat socket.
Q: Why would a trailer still have the small round plug?
A: Older caravans, box trailers and horse floats were factory-fitted with small round plugs when that was the Australian standard. Rewiring the trailer end costs more than fitting an adaptor on the vehicle, so plenty of owners keep the original small round plug and run an adaptor between the two.
Q: Will this adaptor carry an electric brake signal?
A: No. The 7 standard pins on this adaptor carry tail, stop, indicator, reverse, earth and accessory; the pin layout doesn't include a dedicated brake controller output. Electric trailer brakes need a separate hard-wired circuit from your brake controller to the trailer brake magnets, routed outside the adaptor.
Q: Will it work with a 12-pin flat or 13-pin euro trailer?
A: No. This adaptor is strictly 7-pin flat socket on the vehicle side and 7-pin small round plug on the trailer side. For other combinations use the matching adaptor; a small round socket to flat plug for the reverse direction, or a dedicated 12-pin or 13-pin adaptor if your trailer runs those patterns.
Q: What accessories does the 15A per pole rating cover?
A: Standard trailer lighting (tail, stop, indicator, reverse) and basic trailer-mounted accessories like a cabin light or a camping fridge drawing under 15A. Each pin handles up to 15A at 12V independently, so the total current across all pins can go higher. Any single circuit over 15A needs its own dedicated feed, not the adaptor.
Q: Do I need to fuse the circuits?
A: The fuses live at the vehicle end, not the adaptor. Your tow vehicle's factory wiring fuses each lighting circuit back at the fuse box, and any added accessory feed (fridge, camera) runs through its own fuse at the source. The adaptor itself just passes current through, no fuse holder on either end.
Q: How weatherproof is it?
A: The flexible conduit between the two ends handles standard automotive weather protection; rain, dust, mud, corrugated road vibration. For long-term immersion or saltwater exposure, pull the adaptor off between trips and store it dry to extend connector life.
Q: Can I leave it plugged in all the time?
A: Yes. The adaptor is designed to live between vehicle and trailer whenever you're hitched up. Un-hitching unplugs it; leaving it plugged into the vehicle socket between trips is fine as long as the trailer end sits in its socket cover or stays dry.
Q: What vehicles typically have the flat socket?
A: Most Australian 4WDs, utes, vans and SUVs built from the mid-1990s onwards run the flat 7-pin socket as standard. Toyota HiLux, Ford Ranger, Mazda BT-50, Holden Colorado, LandCruiser 200 and 300 series, Nissan Patrol Y62, Isuzu D-Max; all factory-fitted with flat sockets. If your tow vehicle is older than that, you may have a small round socket instead and need the reverse adaptor.
Q: Is there an adaptor that goes the other way?
A: Yes, we also have the small round socket to flat plug adaptor for older vehicles with a small round socket towing a newer trailer with a flat plug. See the Related in our range section above for the linked product.
