Skywatcher Wave 150i Strain Wave GoTo Mount with Pier and Carbon Fibre Tipod Payload 15kg (Payload 25kg with Optional Counter Weight)The Sky Watcher Wave 150i is built based on a strain wave design, also known as harmonic gearing. This drive gear design harbours a number of benefits including highly precise tracking with minimal backlash for capturing long exposure images, and a compact design with a remarkable payload to weight ratio for the use of various equipment while still being convenient for transportation. Wave 150i Mount Features: Working Mode: EQ or AZ Mount weight: 5.