Easy Installation: The telescope spacer rings are simple to install and are a great replacement for old or damaged rings, ensuring reliable use. | PREMIUM QUALITY: Made of high quality aluminum alloy, these photography extension tubes are wear-resistant and built to last. | Precise Manufacturing: Using advanced CNC technology for fine workmanship, these telescope spacer rings provide high precision and durability. | Compatible design: The specifications of the female and male threads of the interface are both M42X0.75mm, ensuring wide compatibility with many models. | Versatile Sizes: This lens extension tube set includes different sizes (3mm/5mm/7mm/10mm/12mm/15mm/20mm/30mm) to fit different models, providing flexibility and convenience.