I bought this product years ago and know it does what its advertised. I use it to water the roots of all my small trees and shrubs in dry periods.
Metal spike is long enough but could be a heavier weight metal; it bends easily. Spike goes into ground easily. Valve for water flow seems a little light weight but has served us well so far. I wouldn't have any more than a trickle going into the ground though; too easy to leave air pockets which would kill roots. All in all for the price it is a great value and it really does deliver water well to tree roots.