What are these connectors used for?

They join battery, ESC and motor leads in RC cars, boats and planes. The 5mm size fits common sport and club-level wiring.

Do they need soldering?

Yes. The wire goes into the cup and is soldered, then heat-shrink covers the joint. There is no crimp option.

For most 1/10-scale and sport builds, yes. High-amp racing rigs usually run 6mm or 8mm bullets for more current headroom.

Four connectors. That covers one battery-to-ESC pair with two spare, or two pairs if you split them.

They mate with standard 5mm female bullets. Check that the low-profile body clears your battery tray or hull before soldering.

10 stores we checked sell it, including AsylumXtreme, Platinum Hobbies, RadioControlSports, RcAbitibi, Tammies Hobbies.

At AsylumXtreme, for $10.99, 15% under what the other stores charge, as of our latest check.

$10.99at AsylumXtremeChecked Nov 11

15% under what the other stores charge

Compared across 10 stores. Prices are checked against each store and labelled with when.

It checks today's price at every store, compares the alternatives and answers in about a minute.