If you're into RC crawling, you know those little drive shaft pins can wear out or get lost. This pack from ShareGoo is a lifesaver. You get 12 super durable screw pins made from hard steel. The size is M4 x 11.5mm (that's the thread size and length), with a pin diameter of 2.5mm. They're universal replacements that fit a bunch of popular 1/10 scale RC crawlers like the Axial SCX10 (including the 90046), Traxxas TRX-4 (and the D90 version), and the Tamiya CC01. They're way stronger than the stock plastic ones, so they're less likely to strip or shear when you're putting down torque on rocks and trails. Having a 12-pack means you've got plenty of spares for future repairs or to share with your RC buddies. Just make sure to check the size matches your specific model before you buy. Super simple upgrade that adds reliability to your rig.