Can this be used for babies who can’t sit up on their own?

Yes it can :). As long as the baby has head control (which typically happens around 4 months). Steve

My seat just arrived and it’s not in a box. Is that normal?

No. That is not normal. It should definitely come in the box. Please return to Amazon and order another one. Cheers, Steve

Can you buy a replacement tray? I'd like to have 2 trays, one for playtime (with toys with suction cups that remain on the tray) one for feeding.

You may be able to get one directly from the company but as a Mom of 4 I would say save your money and just remove the toys before feeding and replace them after. Most suction cup toys aren’t THAT strong that it’s troublesome to remove and replace them.

What is the minimum weight/length requirement? My son is 8 months but was born 14 weeks early and is still tiny for his adjusted age (5.5 months).

I don’t have the exact info you’re looking for...sorry. The manufacturer indicates this product is appropriate from age 4 months. I think the more important factor is your little guy’s head/neck control, rather than his size. My daughter has used this seat from four months on with no problems. In fact, the bigger the baby, the more likely they’ll be able to lock out their legs and scoot the entire seat (which is what my baby has figured out in the last month).

Model Number	101
Product Dimensions	45.72 x 24 x 25.4 cm; 2.25 kg
Item model number	101
Maximum Weight Recommendation	13.61 kg
Material Type	Polyurethane
Number of items	1
Batteries required	No
Is portable	Yes
Item Weight	2.25 kg

Upseat Baby Floor Seat Booster Chair for Sitting Up with Removable Tray for Meals and Playtime, Developed with Physiotherapists for Safe and Healthy Hip Development and Posture (Grey)

Details

Description

Specifications

Common Questions