Zirconia spacers are oven volume reducers — small inert inserts that fill dead airspace in the IQ oven when you're packing less than the full capacity. Without a spacer, a small load in a large oven has dead space above it — you get weaker vapor and uneven extraction. The spacer fills that gap, pressing your herb load toward the heat source for consistent draws even from a half or quarter pack.

Dosing capsules contain the herb inside a pod that loads into the oven as a self-contained unit. Spacers go above a direct oven load (not inside a capsule), filling the volume above however much herb you've packed directly. If you prefer loading the oven directly rather than using capsules, spacers are the mechanism for optimizing small loads.

Yes — spacers are particularly useful in the IQ3's 0.7g oven when packing a smaller amount. The 0.7g capacity is great for full sessions, but for a light load a spacer is important for maintaining draw quality and extraction consistency.

Zirconia ceramic — the same inert material used in the IQ series' vapor path. The spacers don't interact with vapor or terpenes at vaporization temperatures, keeping your session flavor-neutral.