Astrozap Heater Strap for 4" Scopes

AstroZap Dew Heater Strap for 4" Telescopes

Small scopes still suffer from big dew problems. Whether you’re observing with a 4" refractor, Maksutov-Cassegrain, or compact Schmidt-Cassegrain, the AstroZap Dew Heater Strap for 4" telescopes provides essential protection to keep your optics dry and your observing sessions uninterrupted.

This lightweight, fabric-backed strap wraps easily around the front of your optical tube and secures in place with a Velcro closure. Inside, a low-wattage nichrome heating element distributes gentle, even warmth across the corrector plate, lens cell, or dew shield to prevent moisture buildup. The RCA-style connector is compatible with most 12V dew controllers (sold separately), giving you power regulation based on your sky conditions.

It’s a perfect match for travel scopes, grab-and-go rigs, and anyone who doesn’t want a fogged-up lens cutting the night short.

Features:

• Designed for 4" OTAs, including refractors, SCTs, and Maks

• Low-wattage heater element provides safe, even dew protection

• Standard RCA plug works with most 12V dew controllers

• Velcro fastener offers a secure and adjustable fit

• Fabric-backed construction for flexibility and field durability

• Prevents dew buildup on objective lenses, corrector plates, or secondary housings

Observing Tip:

Dew doesn’t play favorites—small scopes are often the first to fog over, especially during quick cooldowns after sunset. Start your heater early to prevent moisture before it forms, and consider pairing it with a small dew shield to reduce power consumption and increase efficiency.