Best Bottomtimer for Technical Diving?

Whats my favorite and what do you use ? Like my merch? Check out the shop: https://teespring.com/de/stores/ise-m... Training: https://is-expl.com Mail to: achim@is-expl.com The Book: in German: https://www.amazon.de/Recreational-Di... in English: https://www.amazon.de/-/en/Achim-R-Sc... Please support me on Patreon and help me to create more content:   / innerspace_explorers   Social Media: Facebook:   / innerspaceexplorers   Instagram:   / innerspace_explorers   If you want to send me something: InnerSpace Explorers Att. Achim Schlöffel Freidankstrasse 3a 81739 München Germany Mail: achim@is-expl.com My other channel in case you are interested :):    / american_runabouts