303Z Vest

A safety vest made by EZ-ON Products of Jupiter, Florida.


This vest is made of webbing and features an adjustable, back-closure zipper. The vest provides upper body restraint, and its back closure can be helpful in thwarting the wearer from taking it off during transport.  An adult must assist the child into the vest, ensure it is properly adjusted, seat the vest-wearing child in a vehicle seat that has an installed EZ-ON floor mount or tether mount, and attach the vest to the mount at each mounting point. 

NOTE:  For anchorage to the vehicle, this safety vest must be used with either of the model-appropriate mounts described here.

  • The floor mount (100FM) requires two tether anchors (included) to be professionally installed in the vehicle and the ability to slip the strap through the seat bight.  
  • The tether mount (100TM) requires the use of one tether anchor (can be factory-installed or purchased from EZ-ON and installed) as well as a vehicle seat belt (or LATCH lower anchors, if a separate Lower LATCH Add-on is purchased).

This vest can also be used on a school bus by utilizing a seat mount style that’s appropriate for those vehicles; however, this SRN Web resource focuses only on use in personal vehicles.

Last updated on February 1, 2024.

Child Requirements

  Pounds Kilograms Inches Centimeters Age (years)
Minimum 31 14.1 no limit no limit 3
Maximum 168* 76.2* no limit no limit no limit

* At higher weights, the vest may also be used as a positional support device if a lap-shoulder belt is worn in the typical fashion over the vest-wearing child (rather than through the vest’s loops).

Measurements and Characteristics

Car Seat Mass (Weight)

< 5 lbs./ 2.3 kgs

Vehicle Fit Characteristics

Outside height: n/a, no plastic shell
Widest outside width: n/a, no plastic shell
Vehicle requirements:
  • If paired with an EZ-ON 100TM mount, vehicle must have a tether anchor. EZ-ON approves tether use at all child weights, but check to see if the vehicle manufacturer sets a limit for use of the tether anchors. Also requires a seat belt unless a Lower LATCH Add On (#225 A) is purchase and used to replace a seat belt. (The vehicle must be equipped with LATCH to use part #225 A.)
  • If paired with an EZ-ON 100FM mount, tether anchors must be professionally installed in the vehicle floor (maximum child weight limit is 168 pounds) and the seat bight must allow the straps/hardware to slip through.

Vest Fit Characteristics

Chest measurements (circumference):  
    XS 18–24 inches/ 46–62 cm
   Small 25–32 inches/ 63–82 cm
   Medium 32–37 inches/ 82–94 cm
    Large and XL 37–42 inches/ 94–107 cm and  43–49 inches/109–124.5 cm
Custom sizing available?: Yes
Crotch strap present?: Yes, on XS, Small, and Medium; order as an add-on for sizes Large and XL.
Crotch strap adjustability:

Yes; Dual straps, each length-adjustable. (A crotch strap extender accessory is no longer available).


  No recline option available; child must be capable of sitting upright (with support of the vest).


Tether present: Yes, on mount (floor mount or tether mount).
Special tethering:
  • If using FM100 (floor mount), the mount’s tether attaches to two heavy-duty tether anchors (included) that the owner has had professionally installed into the vehicle floor, behind the seat.
  • If using the T100 (tether mount) and child exceeds a tether anchor weight limit stated by the vehicle manufacturer, must have a heavy-duty TA (supplied by EZ-ON) professionally installed.

Available Accessories / Add-ons

  • Neck pads (covers shoulder straps)
  • Movement restricting devices: Upper arm straps, wrist straps, ankle straps
  • Snap hook with wings (deterrent to unbuckling at shoulders or hips)
  • Zipper lock (additional deterrent for escapism)
  • Tether anchor retrofit kit (for use with TM100 in vehicles without a factory-installed tether anchor; ensure vehicle maker allows use)
  • Lower LATCH add-on (may replace use of a seat belt in vehicles with LATCH).

Miscellaneous Information

  • MSRP (U.S. dollars): $190.00
  • Company certifies to meet standard:
    • FMVSS213 (U.S.): Yes, if 100TM mount is used.
    • CMVSS 213 (Canadian): No
  • Will ship to Canada? Yes
  • Owner’s manual languages available: English

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