I bought the 5 from Milo in January asa well as the electric pump-I to modified it with a ring around the push button so it cannot turn on in my luggage.
I used mine in Wakatobi for 14 days and 39 dives. I an very pleased with this product .I have learned to use it and it works great and is fast to pump out and make a dive. Nothing like the green flashing light to make you feel safe. Mine is in a Subal ND30 housing. It is smaller than the backscatter one and theirs has no lights to keep you informed on the vacuum holding like the sentinel 5.
I recommend this product.