The Lisle 60800 Heater Core Backflush Tool with Air is a great product that serves a specific need and does it well (and affordably).Have been fighting for years with the common problem of NO HEAT from drivers side vents on my 2011 Jeep Wrangler. Watched many videos on how to fix this and bought a couple hoses, connectors, etc. and tried a straight garden hose water flush - didn't work (not much, if any, sediment came out). Drove with no heat for another season thinking I had to replace my heater core - something I was not looking forward to.In a desperate attempt to get heat in the middle of winter, I watched videos about replacing heater core (and was ready to pay the price) when I came across a video of a guy using air + water to clear heater core blockages using a competing product (MightyVac). Since that product was pretty expensive, I searched and found this Lisle version - which frankly is overpriced for what it is BUT worth every penny for the fix it provides.How I cleared my blockage and got heat back: Cut a sacrificial hose into 6 foot sections, attached 1/2" x 8" copper pipe pieces with clamps, thus creating created an inlet & outlet hose to plug into my heater core supply lines. I clamp/pinched radiator top hose with a hose clamp tool to avoid coolant loss. I pushed remaining coolant out of heater core water from garden hose then blew remaining water out of heater core by mouth. Filled heater core with cleaning vinegar and let sit for 1 hour. Hooked up Lisle air flusher and ran it (100 PSI from small pancake compressor) with hose water to try to clear blockage in core. A small amount of silt came out first time into 5 gallon bucket. repeated the hose water flush 5 more times then reversed the hoses to backflush the opposite direction. Again, only a few small black flakes every flush. Redid the vinegar treatment and repeated the 5x flush never getting much more than a couple black specks out each time.Filled core with vinegar & let sit overnight. Redid whole procedure 5x each way getting a couple specks each time (a couple times I got a couple larger chunk/specks/flakes). Would this ever end?Next day I used ThoroFlush instead of Vinegar and repeated the same procedure 5x each way (going both directions is actually what works IMO). FINALLY, upon looking closely into each 5 gal clear water flush, I wasn't seeing any more minute specs. I probably repeated the 5 gallon flush & dump 30+ times in all.Removed my hoses and blew final air out of heater core. Used Funnel to refill heater core with coolant. Reattached inlet/outlet hoses back to water pump and thermostat. Used a coolant funnel fill kit like this to get air out of system https://www.amazon.com/dp/B01I40ZQWE?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_4And I GOT HEAT !!! Highly recommend the Lisle heater core flush tool as nothing else worked for me.Note: Using the Lisle gun requires you to use two hands & press on/off the air injection to cavitate the flow and knock particles free. Yes, I used 100 psi going in but didn't damage anything. Also, There is a lot of hooking and unhooking the worm clamps to reverse flow, add vinegar with funnel, etc. so I used a small battery driver to tighten, loosen the clamps each time - couldn't imagine doing it 30+ times with a screwdriver.