For metal rings — yes.
All our metal rings (tungsten, titanium, stainless steel, black zirconium, tantalum, damascus) are available in both full and half sizes (e.g. 8, 8.5, 9, 9.5). So if you land between two sizes, you can order the half size that fits best.
For silicone rings — no half sizes.
Silicone is naturally flexible and stretches and adapts with wear over time, so the in-between fit takes care of itself. If you're between sizes on a silicone ring, size down — it'll loosen slightly as you wear it in.