http://www.jpspecialties.com/Waterstop_for_Concrete_Joints/dumbbell.html Dumbbell waterstop is usually used in below grade applications, where limited movement is expected. Dumbbell waterstop can be installed in construction and contraction (control) joints; whereas, dumbbell centerbulb can be installed in construction, control, and expansion joints. The large centerbulb (1-1/2” outer diameter) on the JP949 (and JP1149) waterstop profile, coupled with the outstanding mechanical properties of our thermoplastic vulcanizate and large endbulb anchors, enable the product to withstand large -scale joint movement (seismic, settlement, etc.). JP648, JP948, JP949 and JP1149 are all 3/8” thick... The largest and thickest profiles available in the industry! Like all our thermoplastic vulcanizate waterstops, Earth Shield dumbbell waterstop can be heat-welded using a standard waterstop splicing iron. This allows for easy field fabrications, and allows the waterstop to function as a continuous, homogeneous, fluid-tight diaphragm. Waterstop change of directions can be purchased along with straight roll stock, and custom, fit-to-print waterstop modules are produced to order. Prefabricated ells, tees, tank pads, column fittings, and many others are in stock and ready to ship. Complete PDF & DWG Details can be found here Earth Shield Thermoplastic Vulcanizate Waterstop Product Catalog Earth Shield Thermoplastic Vulcanizate Waterstop Master Spec CSI 3-part Long Form in PDF format  http://www.jpspecialties.com/Waterstop_for_Concrete_Joints/dumbbell.html#0 0b6aab88-4fed-4b6c-94bb-efa85a7f6ab0 http://www.jpspecialties.com/Waterstop_for_Concrete_Joints/dumbbell_files/Media/dumbbell/thumb.jpg http://www.jpspecialties.com/Waterstop_for_Concrete_Joints/dumbbell_files/Media/dumbbell/micro.jpg <div style="padding: 0px; " class="style_External_194_48"><div class="style_5"><p style="padding-top: 0pt; " class="paragraph_style_4"><br/></p></div></div>