Kyosho YKW011 Kanai Tools Spanner 5.5mm 7.0mm

A double-ended spanner wrench from the Kanai Tools line, with 5.5mm and 7.0mm openings.

These are the small-fastener sizes on a radio control car: 5.5mm is the standard wheel nut across most of Kyosho's electric and nitro range, and 7.0mm covers link ends, lock nuts and various chassis hardware. Having a proper spanner for them rather than reaching for pliers is what keeps flats square, and a rounded fastener is a genuine problem because it usually cannot be removed cleanly once it has gone.

A double-ended spanner also earns its place in the pit box simply by being one tool instead of two, which matters when you are working against the clock between heats.

This is a pit tool rather than a vehicle part. Kyosho's compatibility list for it is unusually broad, spanning the Inferno MP9 TKI3 and TKI4, MP10 and MP10T, Inferno NEO 3.0 and 4.0, Inferno GT2 and GT3, the Mad Force Kruiser 2.0 and even their Calmato and SQS Warbird airplanes. A larger 6.5mm and 8.0mm spanner is available separately.