Portable Hangboard for climbing 20/15 mm

I've made this portable fingerboard / hangboard for finger and grip strength training since I didn't want to drill any holes in my apartment walls. It's also a great tool for warming up your fingers when bouldering or doing outdoor climbing.

The hangboard has 20 mm and 15 mm edges. The middle hole for the cord is 5 mm and it has channels on each side along the hangboard, so once under load it won't rotate.

All that is required for training is a piece of cord up to 5 mm thick so that it can pass though the middle hole, a carabiner and some elastic band which can be purchased at any sport goods store. I've got a pack of 3 different stiffness bands, so I can change them depending if I'm going for my max pull or just warming up.

Overall size of the hangboard is 11 cm x 11 cm x 3.5 cm.