AT-50 Package of 4 additional 50mm dollies (Acessory for PosiTest AT-M Manual Pull-Off Adhesion Tester - Complete Kit) Go to amazon.com Related posts Check expert advices for positest ata 50? DescriptionThe AT-50 Package of 4 additional 50mm dollies is an accessory or spare part for the PosiTest AT-M Manual Pull-Off Adhesion Tester.