Do not judge by a lifestyle stick-in-hand crop. Judge by 10 mm thickness and 4.4 V peak on the D91 plate.
Step 1. Read D91: 20 × 82 × 10 mm. If a listing says “slim” and never prints 10 mm, it is not answering WINDBAR D91 vs Hyde Edge slim.
Step 2. Read 4.4 V peak flavor drive. Do not copy a Hyde voltage onto D91.
Step 3. Confirm a complete front catalog still. The full card is in frame, mouthpiece to base. Do not use a tall wrap strip Google would square-crop.
Step 4. Color is identity. Piano Black and Transformative Teal share the millimetres.
Step 5. If you want 4.4 V in math, open the WINDBAR ohm’s law calculator and enter 4.4 V plus the ohm from the insert. Packaging wins.








