SV172 Dew Heater Strip can be used as a wrist strap or knee strap to protect you from cold weather or emergency condition. Designed for astronomy telescopes, and compatible with DSLR camera lens: protecting optical devices like telescope and camera from fogging or freezing. Imitating OK cloth, SBR and Black-T three-layer keep warm material reducing heat dissipation, and the inner surface does not wrinkle after being bent. It fits the lens barrel better and which increases the keep warm effect. SV241 Pro Astronomical Telescope Photography Power Management Box is a compact, durable power solution with 5 DC outputs, USB ports, and PWM channels for cameras, heaters, and sensors; Suitable for nighttime observation and astronomical photography. Our SV241 Pro Power Management Box's system offers static electricity protection, reverse connection and backflow prevention, plus USB 3.0 and DC filtering. Fuse, voltage, current, and short-circuit protections ensure stable power, while intelligent detection and auto-restart keep devices safe and running smoothly.