Defender Reha (Booster Seat mode)

A booster seat with a positional harness made by Thomashilfen, based in the U.S. in Seattle, WA.


This booster seat keeps a child in position using an internal harness and offers many accessories for customized child positioning, comfort, and ease of use.  In booster mode, the occupant MUST wear a lap-shoulder belt.  (See Defender Reha in Harness Mode for details on this model used as a child restraint with an internal harness.  If ordering Defender Reha specifically for use as a positional booster, order Defender Reha Booster Seat rather than Car Seat so it will come with a crotch strap extender for larger occupants.)

Thomashilfen Defender Reha Booster Seat

Last updated on February 1, 2024.

Child Requirements

  Pounds Kilograms Inches Centimeters Age (years)
Minimum 30 (40 in Canada) 13.6 (18.1 in Canada) 34 86.4 n/a
Maximum 110 50 57 144.8 n/a

Measurements and Characteristics

Car Seat Mass (Weight)

22 lbs./10 kg

Vehicle Fit Characteristics

Outside height—minimum:
Outside height—maximum:
26.5 in./67.3 cm
33.5 in./85 cm
  Widest outside width: 18.25 in./46.3 cm
  Vehicle requirements: lap-shoulder belt

Child Fit Characteristics

  Narrowest torso area: 6.5 inch/ 16.5 cm
  Narrowest seat cushion width: 8.5 in./21.5 cm
  Seat cushion depth: 13.5 in./33 cm
  Seat cushion depth extender options: Yes; provides an additional 5 in./13cm of seat cushion depth

Harness Fit Characteristics

  Harness Type: Five-point (positional only in booster mode)
  Number of harness height positions: 9
  CR bight to lowest shoulder height position: 10 in./25 cm
  CR bight to highest shoulder height position: 19.5 in./49.5 cm  (with cushion foam removed, per instructions)
  Crotch strap present: Yes
  Crotch strap adjustability: Yes, by position and length
  CR bight to nearest crotch strap position: 5.5 in./14 cm
  CR bight to farthest crotch strap position: 9.5 in./24 cm (with cushion foam removed, per instructions)


  Semi-recline allowed in forward-facing position: Yes; 10° recline with seat wedge underneath (accessory, described below)
  Other: CR back reclines to match angle of vehicle seatback


  Tether present: Yes, but tether may not be used in booster mode. (LA attachment use in booster mode is allowed unless footrest accessory adapter plate is in use.)  
  Special tethering: n/a

Accessories / Add-ons

Standard accessories:

  • lateral seat support
  • lateral trunk support
  • head support
  • small soft crotch pad
  • chest clip
  • shoulder pads
  • cup holder
  • crotch strap extension

Add-on accessories:

  • Swivel base with lower anchor connectors
  • Footrest, with adaptor and footrest pad (adjustable angle; short is 4.7 in./12 cm and long is 7.1 in./18 cm)
  • Table (soft play tray that provides body support and limits access to the buckle )
  • Abduction block (rigid crotch pommel for extra medial thigh support)
  • Seat wedge (provides 10° angle of recline)
  • Large soft crotch pad
  • Seat depth extender (5 in./13 cm)

Miscellaneous Information

  • MSRP (U.S. dollars): $995.00
  • Company certifies to meet standard:
    • FMVSS213 (U.S.): Yes
    • CMVSS 213 (Canadian): Yes
  • Will ship to Canada? Yes
  • Owner’s manual languages available: English, French

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