A sliding transfer bench is a type of shower bench that is designed to make it easier for people with mobility issues to get in and out of the shower. It typically features the following components:

1. Seat: The seat of a sliding transfer bench is typically made of durable plastic and has drainage holes to allow water to drain away from the user. It may also have a textured surface to prevent slipping.
2. Backrest: Many sliding transfer benches come with a backrest for added comfort and support. The backrest may be adjustable and can be removed if desired.
3. Armrests: Some sliding transfer benches have armrests to provide additional support and stability for the user.
4. Legs: The legs of a sliding transfer bench are typically adjustable to accommodate different bathtub heights. They may also have suction cups at the bottom to prevent the bench from sliding around in the tub.
5. Sliding seat: The unique feature of a sliding transfer bench is that the seat slides back and forth, allowing the user to sit on the bench outside of the bathtub and then slide into the shower without having to step over the side of the tub. This feature can be particularly helpful for people with limited mobility or who are recovering from surgery or injury.
6. Hand-held showerhead holder: Many sliding transfer benches also come with a holder for a hand-held showerhead, making it easy for the user to wash themselves while sitting on the bench.

Overall, a sliding transfer bench can be an excellent option for people who have difficulty getting in and out of the shower due to mobility issues. The sliding seat feature makes it easier and safer for users to access the shower, and the other features provide additional support and stability during use.