Hang your loupe around your neck to keep it handy. If you're like us our pockets sometimes get full of rocks which makes it hard to find the loupe. Of course rocks tend to "polish" the loupe. (Polishing is nothing more than scratching with finer and finer scratches.) With the loupe on the lanyard it's readily available for inspecting that new find. Lanyards work to keep you from walking away and leaving the loupe or having the loupe walk away and leave you!
Our nylon lanyards have a quick release buckle like you'll find on a backpack. The quick release buckle allows you to disconnect the majority of the lanyard when you just need to stick the loupe in your pocket.