Full Aperture Solar Filter 173mm Inner Diameter 170mm

Full Aperture Solar Filter 170mm
Film diameter: Approximately 135mm/5.3”
Outer diameter: Approximately 173mm/6.8”
Inner diameter: Approximately 170m/6.69”
(Please measure the outer diameter of the telescope first. Choose the solar filter inner diameter a little larger than the outer diameter of the telescope).

Polymer film features:
Optical density 5.0
Solar transmittance 0%
Ultraviolet light blocked >99%
ASTM and ISO certified

NEVER take pictures of a solar eclipse without the aperture filter properly installed as otherwise it could cause permanent injuries to both your eyes and your device;
Filters that are damaged or separated from their mountings should be discarded;
ALWAYS turn around and put down your device for a rest after taking pictures of the sun or an eclipse and always limit your continuous viewing to three minutes at a time;
NEVER let minors take pictures of eclipses with aperture filters without supervision;
ONLY clean with a soft cloth or tissue and store them at a safe place;
Discard your aperture filters after 10 years of use.

Bookishbunny and our manufacturer Cangnan County Qiwei Craft Co. Ltd. are listed on AAS website (https://eclipse.aas.org/eye-safety/viewers-filters). 
Bookishbunny by East Commerce is listed on Qiwei County's website under the tab Official Authorized Distributor (https://qiweisolareclipse.com/pages/official-authorized-distributor).

Safety Tips for Observing Eclipse 

During an eclipse, it is never safe to look directly at the Sun without specialized eye protection designed for solar viewing. When watching an annular solar eclipse directly with your eyes you must look through safe solar viewing glasses (“eclipse glasses”) or a safe handheld solar viewer at all times. Safe solar viewers are thousands of times darker and must comply with the ISO 12312-2 international standard.