If you didn't know, you can download a free GNS 400/500 trainer from Garmin. It's helping me learn the GNS 430 from my chair at home! : r/flying
Garmin 400W/500W Trainer - CFILOU-Airplane Flight Instruction, Lessons and FAA Flight Reviews in New Jersey
Garmin Forerunner 305 Wrist-Worn GPS Personal Training Device with Heart Rate Monitor (discontinued by manufacturer) (discountinued by manufacturer) : Amazon.co.uk: Fashion