This in one of those "Why didn't they think of this before" pieces of equipment. A simple screw top design lets you adjust and keep the indicator in place.
Oros Fly Fishing Strike Indicators are made with a biodegradable additive that rapidly enhances the ability for plastic to biodegrade in natural environments, not in normal use.
Oros strike indicators enclose fastening hardware inside of two foam hemispheres. When closed, the foam compress creating a pressure fit lock that keeps it on the line and in place, without kinking. Large screw threads make securing it to the line effortless, and it it's even easier to lock in place with wet hands.