3 mL to 10 mL Vial Adapter
Holds a 3 mL Vial in a 10 mL Vial Case Slot
Vial Size Chart
Vial sizes refer to liquid capacity. Below are the approximate dimensions of each common vial — match your vial to the size this case is built for.
| Vial Size | Approx. Size (Ø × H) | Common Contents |
|---|---|---|
| 1 mL | 11 × 32 mm | Small vials |
| 2 mL | 14 × 35 mm | Standard vials |
| 3 mL | 16 × 35 mm | Standard vials |
| 5 mL | 20 × 38 mm | Larger vials |
| 10 mL | 22 × 50 mm | Bottles & diluents |
| 20 mL | 30 × 57 mm | Multi-dose bottles |
| 30 mL | 36 × 63 mm | Large bottles, bulk |
| 50 mL | 40 × 75 mm | Bulk storage |
| 100 mL | 52 × 95 mm | Bulk storage |
Dimensions are approximate and vary slightly by manufacturer. Ø = diameter, H = height (excluding cap). When in doubt, measure your vial’s widest point and height.
- Hard-shell impact protection
- Fridge & freezer safe
- Keeps vials organized & secure
- TSA friendly & travel ready
- Ships in 24–48 hours
You picked a Blemished item
This version has a minor cosmetic or print defect — a small mark, blemish, or imperfection from the 3D-printing process. It’s offered at a lower price because we can’t sell it as new.
- 100% functional — protects your vials exactly the same.
- Cosmetic flaw only — appearance varies slightly unit to unit.
- Discounted & final sale.
Turn any 10 mL slot in your vial case into a 3 mL slot. The adapter drops into the 10 mL slot and holds one standard 3 mL vial upright and snug, so you can carry 3 mL and 10 mL vials in the same case without the small vials tipping or rattling. Lift it out any time and the slot takes a 10 mL vial again.
How it works
- Drop the adapter into an empty 10 mL slot.
- Set a 3 mL vial into the adapter.
- Close the lid as usual - the 3 mL vial sits at the same height as a 10 mL vial, so the lid still closes.
Which fit do I need?
- Standard 10 mL Slot (26 mm): every VialCase shop case with 10 mL slots (slot 26 mm / 1.02″ across). Adapter 25.0 mm × 45 mm (0.98″ × 1.77″)
- Slim 10 mL Slot (23 mm): custom-built cases with slim 10 mL slots (23 mm / 0.91″ across). Adapter 22.0 mm × 45 mm (0.87″ × 1.77″)
What Fits
- One standard 3 mL vial per adapter, up to 17 mm (0.67″) across and 41 mm (1.61″) tall with the cap on
- Inside opening: 17.5 mm (0.69″) across × 31 mm (1.22″) deep
Key Features
- Same fit as our 3 mL slots - the vial sits snug, not loose
- Two finger notches let you grab the vial, and the adapter stands a little above the slot so it lifts out easily
- Raised floor keeps the 3 mL vial at 10 mL vial height, so the lid closes
- No tools, no glue - move adapters between slots whenever you like
- Made to order in Las Vegas, Nevada in Black, Cobalt Blue, Cyber Green, Purple, Galaxy Purple, Red or Hot Pink
Care
- Hand wash only with cold water
- Not dishwasher safe
Good to know
- Vials and case are not included
- Fits VialCase 10 mL slots; for other brands, measure the slot first (26 mm or 23 mm across)
- Each adapter is 3D printed to order
Shipping
- Free shipping on all orders over $99.99.
- Made to order — ships in 24–48 hours.
- Tracking provided on every order.
Returns
- 30-day money-back guarantee — love it or return it.
- No-questions-asked returns on unused items.
- Contact us and we'll make it right.
Customer Reviews
Real, verified reviews and photos from VialCase customers.
Why VialCase vs. a Generic Box
Built for vials — not a repurposed tackle box.
| Feature | VialCase | Generic Storage Box |
|---|---|---|
| Custom-fit vial slots | ✓ | ✗ |
| Hard-shell impact protection | ✓ | ✗ |
| Fridge & freezer safe | ✓ | ✗ |
| Dedicated diluent-bottle slot | ✓ | ✗ |
| Made in the USA | ✓ | ✗ |
| 30-day money-back guarantee | ✓ | ✗ |
| 1,600+ verified reviews | ✓ | ✗ |
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