Best Car Seats · Diono · Updated June 2026

Diono Radian 3QXT SafePlus Convertible Car Seat: specs and price (2026)

Diono Radian 3QXT SafePlus Convertible Car Seat has a US price of $449.99 (MSRP $449.99 per babycubby.com and REBEL full price; frequently discounted to ~$225 at majors). Below is its full, sourced spec sheet — every value links to the source and the date we captured it.

Specifications

Price (US)	$449.99 MSRP $449.99 per babycubby.com and REBEL full price; frequently discounted to ~$225 at majors
Brand	Diono
Released	2021
type	all_in_one
min weight lb	4
max weight lb	120
height limit in	57 in
install	both
steel frame	Yes
expiration years	10
release	2021

Source: babycubby.com (verified 2026-06-19) · corroborated by amazon.com. SOURCE FIXED: draft's store.diono.com URL returned HTTP 423 Locked; replaced with working babycubby.com listing. Re-verified 2026-06-19: price $449.99, RF 4-50 lb, FF 22-65 lb, booster 40-120 lb, max user height 57.1 in. Reinforced automotive-grade high-strength steel core and SafePlus steel anti-rebound bar confirmed. 10 years of use. Release year 2021 per csftl.org review.

Frequently asked questions

How much does the Diono Radian 3QXT SafePlus Convertible Car Seat cost?

The Diono Radian 3QXT SafePlus Convertible Car Seat has a US price of $449.99 (MSRP $449.99 per babycubby.com and REBEL full price; frequently discounted to ~$225 at majors), as of 2026-06-19.

When was the Diono Radian 3QXT SafePlus Convertible Car Seat released?

The Diono Radian 3QXT SafePlus Convertible Car Seat was released 2021.

What are the Diono Radian 3QXT SafePlus Convertible Car Seat's key specs?

Diono Radian 3QXT SafePlus Convertible Car Seat (Diono): type all_in_one, min weight lb 4, max weight lb 120, height limit in 57 in, install both. Full sourced spec sheet verified 2026-06-19.