Price: $38.80 CAD
TurboKlone polyethylene collars are more durable and maintain shape longer than other neoprene collars and are configured for easy insertion of cuttings.
Most importantly, these collars don't choke your cuttings.
They last a long time and are fully washable, but it's still a good idea to change them out periodically. Also, it's handy to have some extras around when a replacement is needed.