Surface material: coated paper+stickers+foil Surface color: black / white / bar code, or custom working principle: LC shock circuit Q value: Q≧90 Detection distance: 0.90~1.2 meters Unlock mode: decoding board decoding Center frequency: 8.2MHZ Size: φ40mm, 40×40mm, 30×40mm, 50×40mm, can customized Anti-human shielding capacity: high