Last updated: August 19, 2026. Contact support@Optcla.com or +1 (707) 215-3921 for sizing help before personalizing.
How to measure
Use a soft measuring tape around the base of your dog's neck where the collar normally rests. Keep the tape level and leave enough space to slide two fingers between the tape and neck. Do not measure an old collar laid flat unless you know which points represent its fitted circumference. Take the pre-order size chart and measurement checklist with you before opening the customizer.
Current size ranges
- Small: 10-14 inches
- Medium: 13-18 inches
- Large: 16-22 inches
- XL: 19-27 inches
Choose a size that places the measurement comfortably inside the adjustment range, not at an extreme edge.
Two-finger fit check
After fitting, two fingers should slide beneath the collar without forcing them. The collar should not pass over the dog's head when gently pulled forward. Recheck from more than one angle.
Fitting a growing puppy
Measure the neck your puppy has today and choose a range that fits securely now. Do not rely on breed or expected adult size. Recheck frequently during rapid growth and after coat changes. Read the complete puppy collar sizing and growth guide.
Before every walk
Inspect the buckle, D-ring, adjustment point, collar material, reflective strip and nameplate. Replace the collar if any component is cracked, loose, sharply worn or no longer closes securely. Follow the complete collar inspection checklist.
Frequently asked questions
What if the measurement is between sizes?
Choose the range that keeps the measurement comfortably away from an extreme, or contact support before personalizing.
Does the two-finger rule work for every dog?
It is a useful general check, but head shape, neck shape, coat and activity also matter. Seek qualified advice when unsure.
Important use note
This is an everyday identification and walking collar, not tie-out equipment. Fit needs vary by dog shape, coat, age and activity. Ask a qualified trainer or veterinarian when you are unsure about appropriate equipment.
Choose size and personalize