AQUATEK CO2 Brass Bubble Counter with Integrated Check Valve

Designed to be compatible with AQUATEK CO2 Regulators (Models: Basic R-76, Premium R-76-1 and Mini R-78). Attaches directly to AQUATEK regulator without tubing or extension. Built-in check valve prevents back-siphoning and protects CO2 system. Be aware of Knock-Off. Aquatek is the sole authorized distributor to sell this bubble counter on Amazon. Be sure to purchase from Aquatek and fulfilled by Amazon (Sold by Aquatek and Fulfilled by Amazon, not from third-party seller) for compatibility and genuine parts made of highest quality. Look for original package and color (shown in the product images). Instructions: 1.Unscrew the air tube tightening nut completely and remove the black rubber o-ring. 2.Remove the lid of the brass bubble counter. Fill the bubble counter chamber with water until ¾ full; close the lid tightly. 3.Place the black o-ring onto the outlet of your regulator. O-ring should be secured in the groove before the thread. 4.Screw the bubble counter onto the outlet of your regulator 5.Connect CO2 air tube to the brass bubble counter by unscrewing the tightening nut completely, fit one end of air tube through the nut and fit it over the outlet of the bubble counter, and then tighten the nut down.