How to build an efficient signal blocker

Recommended high-efficiency signal blocker products
1. CM4 Box portable GSM/GPS jammer
https://www.thejammerblocker.com/buy-cm4-box-portable-jammer-for-gsm-gps-locator/
CM4 is designed to block GSM communications and GPS positioning signals. Its features include:
- Coverage frequency: GPS L1 (1575MHz), GSM 850/900/1800/1900MHz
- Interference range: 5-15 meters (depending on the environment)
- Built-in rechargeable lithium battery, 2-4 hours of battery life
- Lightweight and portable design (12×8×3cm), suitable for carrying around
- One-button operation, simple and easy to use

2. G9-Pro Compact USB GSM/GPS Jammer
https://www.thejammerblocker.com/g9-pro-compact-usb-gsm-gps-jammer-plug-and-play/
G9-Pro stands out with its unique USB interface design:
- Plug and play design, powered by USB port
- Covers GSM 2G/3G/4G and GPS L1 bands
- Compact size (8×5×2cm), easy to hide
- No built-in battery, relies on external power supply, suitable for vehicle or fixed use
- Low power consumption design, low heat generation during operation

3. P-US-F5 Ultrasonic Recording Jammer
https://www.thejammerblocker.com/p-us-f5-ultrasonic-recorder-jammer-mobile-power-bank/
- Emits 20-24KHz ultrasonic waves
- Disguised as a mobile power bank, highly concealed
- 10000mAh large-capacity battery, also used as a power bank
- Does not affect normal calls, only targets recording devices
- Effective range 3-8 meters

4. D-004 200W vehicle-mounted FPV drone signal blocker
https://www.thejammerblocker.com/d-004-200w-4-bands-vehicle-fpv-drone-signal-blocker/
D-004 is a high-power professional-grade blocker:
- 200W high power output, interference range can reach 300-500 meters
- Covers 2.4GHz/5.8GHz WiFi and FPV drone control bands
- Designed for vehicle-mounted use, supports 12/24V power input
- Four-antenna system, full coverage
- Metal casing, excellent heat dissipation performance

https://www.thejammerblocker.com/a-tag-smart-apple-air-tag-tracker-mfi-certified-anti-lost-locator/