Black Holes are a unique and innovative top feed dripper manufactured for use in hydroponic applications. 1/2 in and 1/4 in barb option. 1/4 in barb is compatible with standard drip emitters by plugging them into the barb (rec. 2 GPH emitter). Designed with 6 beveled emitter holes and a raised flat at each one on the inside trough that together reduce clogging. 100% Made in the USA by 100% recycled plastic.