Review on 🔩 Eheim - 2 Ventouses + Clips 12/16 (4014100) - Powerful Suction and Secure Attachment for Optimal Functionality by Dave Howard

These are great suction cups to replace the old Eheim suction cups - they hold both inlet and outlet plastic parts perfectly. The only problem with them is that they wear out pretty quickly. They become unwieldy and lose their suction power. Let's say the suction tube isn't sucking up your glass and you leave it on for a while when you try to reattach it, it just doesn't have the same initial grip. , the trick is to always make sure you are attached to the glass otherwise you will often have to buy replacement cups.