Take a look at firefly GOTO seat

Firefly

Product Care

Clinical Setup for Postural Management

The clinical setup of the product should be completed by a technically and clinically competent person who has been trained in the use of the product. Leckey recommend a written record is maintained of all clinical setups for this product.

Seat Depth and Backrest Angle Adjustment
The seat depth adjustment allows for growth and also allows for exact femoral support. The backrest can also be a set to your preferred angle. Loosening the two sets of allen bolts (a) at either side of the chair alters both of these adjustments. Once these bolts are loosened, the backrest can then be adjusted to the required seat depth and angle and once in position the allen bolts (a) should be retightened securely.
Do not adjust while the user is in the seat.
 
Backrest Height Adjustment
The overall height of the backrest can be adjusted by loosening the two sets of allen bolts (a) and then raising and lowing the backrest to the required shoulder height of the user. Once in position the allen bolts (a) should be retightened securely.
 
Footplate
The footplate can be height adjusted for varying lower leg lengths and also to aid manoeuvrability. To height adjust the footplate, the four allen bolts (a) should be loosened, the footplate raised or lowered to the desired position and the four allen bolts (a) re-tighten securely. A footplate with straps is also available. To position the child’s feet, simply secure the Velcro straps.
 
Flexible Lateral Supports
To adjust the flexible lateral supports in height and width, loosen the allen bolts (a), select the most appropriate position for your child and then re-tighten the allen bolts securely in the desired position. The strap can then be secured at the front to give the optimal position for the child.

 
Adjusting the pommel
The depth of the pommel can be adjusted by loosening the bolt/knob, positioning and then re-tightening.