Questions about Gym Universe Door stretch

Gym Universe's pull-up bar is designed to be used on various types of doors, but it is important to check that the specific pull-up bar is compatible with wooden doors. - Check the assembly instructions and specifications of the pull-up bar to see if it is suitable for wooden doors. - Make sure the pull-up bar can support the right size and weight for your specific wooden door. It's always a good idea to contact Gym Universe's customer service for specific confirmation before mounting the pull-up bar on a wooden door.

Do you mean between trees? The manufacturer states that if wood, then it should be solid wood doors.