The cold frame makes it possible to start growing flowers and/or plants early in the year. The walls and the lids of the mini-greenhouse are made of polycarbonate. The cold frame has no floor and is simply placed over the young plants or seeds, so you can plant them directly into the earth. The 4 lids can be put up so you are able to reach every corner of the mini-greenhouse.This material is transparent. The cold frame is heat, form and impact resistant and highly durable. The material is also UV-resistant and will save up to 40% more warmth in comparison to glass. The cold frame is able to withstand temperatures ranging from -13°F up to +140°F. During winter you can use this mini-greenhouse to protect your young plants or seeds against frost. During the summer, you can increase the harvest time. You yourself create and control the amount of light, air, heat and humidity.Material: PolycarbonateUV-resistant: yesDimensions: 3' 6" x 1' 4" x 3' 7" (w x h x d)Number of lids: 4Frame material: AluminumWaterproof: yesShock and impact resistant: yes