Gee, I see the price on the (backordered) K&N SP-2704 is now $95 each from a Rotax distributor. The one without the safety wire tab might be a good alternate for the RV12. I think the tab is likely designed for pusher applications of the engine where a loose air filter could go through the prop. Like John, I have never safety wired mine. The KAI is very specific about safety wiring the oil drain plug, the magnetic inspection plug, and the oil pressure regulator plug but is mute on safetying the air filters.