Based on this product's specifications, here are some alternatives and similar models
Omnitronic Distance Rod Bass Box/High Frequency Box M20 model 60004558
Summary description:
Distance rod designed for Bass Box and High Frequency Box with M20 thread, suitable for mounting loudspeaker cabinets and poles. Manufactured by Omnitronic (model 60004558), it provides a secure threaded connection between speaker stands and cabinets. Ideal for PA setups, live sound and installations where stable pole-to-box attachment is required.