This propagator is perfectly shaped to fit on a windowsill. Comprises 53.5x 11cm (21x 414) propagator with re-useable waterproof base tray & lid, & 24 35mm Jiffy 7 pellets, plus 2 packs of 12 Jiffy 7 pellets to refill it with. Jiffy 7R Propagator Kits: Providing all you need to take you through from sowing to planting stage, these propagator kits include base trays, propagator lids & Jiffy 7 pellets. Perhaps best described as a compressed pot complete with compost, these pellets swell to seven times their own size when watered. Surrounded by a biodegradable net, they make superb little pots for seed sowing & planting cuttings. The growing medium has the ideal water/air ratio & the young roots can easily penetrate the netting, so when planting you just plant the whole pot complete with plant, without causing any damage to the roots!