The TFL muscle - Tensor Fascia Latae - responds really well to the manta foam roller. It is a small muscle on the outside of the hip, and is not easy to stretch yourself. In a seated posture this muscle is in a shortened position so is very prone to getting tight.
A tight TFL will often contain trigger points within the muscle, causing pain or discomfort on the outside of the hip and can cause tension the the ITB. This in turn can lead to knee and hip pain.
The central ridges of the manta foam roller are slim enough to target this muscle to release it, treat any tigger points reducing pain, easing fascial tension through the IT band, and improve hip function.